JPH0151875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switching signal generating circuit used in emergency lighting devices and the like.

A conventional emergency lighting device will be explained based on FIGS. 1 to 7. This emergency lighting device
As shown in the figure, the switching signal generation circuit is connected to the commercial power source, the distribution board is connected to the two power lines A ₁ and A ₂ drawn out from the commercial power source, and the output of the switching signal generation circuit is connected to the signal line. Power line supplied to the distribution board through A ₃ and A ₄ and drawn out from the distribution board
Connect the switching circuit to A ₅ and A ₆ , and also connect the power line A ₅
Connect the terminal X 2, which is the common power input terminal of the charging circuit V _a of the emergency lighting equipment and the normal lighting circuit V _b , to the power supply line A 6, and connect the terminal X ₂ , which is the common power input terminal of the charging circuit V _a, to the power supply line A ₆ . ₃ is connected to the COM− of the contact _{ry 1} of the relay RY 1 which responds to the switching circuit of the terminal X ₁ which is the other power input terminal of the normal lighting circuit V _b .
Connected through NO. In addition, S ₁ is the locking lighting interlocking contact, and the shorting wire L ₁ of the switching signal generation circuit
If you remove it and connect it to that part, you can control the switching signal generation circuit. In addition, _S2 is an automatic fire alarm equipment transfer contact, and if the shorting wire _L2 is removed and connected to that part, the switching signal generation circuit can be controlled in the same way. Furthermore, NFB is a circuit breaker built into the distribution board, and H is a switching signal generating circuit that transmits the on and off signals given from the switching circuit to the switching circuit, and a short circuit or disconnection of signal lines A ₃ and A ₄ has occurred. MC is an electromagnetic contactor that responds to the power failure compensation circuit H, which is a power failure compensation circuit that forces the regular lighting circuit _Vb to turn on at times to prevent emergency lighting.

The switching signal generation circuit is as shown in FIG.
Contact RY ₂ of relay RY ₂ is connected to COM− by commercial power supply.
A voltage is constantly generated between the signal lines A ₃ and A ₄ via the NC (the contact state shown in the diagram indicates the lighting state), and the switch SW ₁ is set at the time t as shown in FIG. 6A. When switching from the NC (lit) side to the NO (unlit) side at step ₁ , relay RY ₃ is energized as shown in Figure 6B, and contacts ry _3a , ry _3b , and ry _3c are switched from the NC side to the NO side. , the short-time energization timer TM ₁ for turning off the light is energized, and the short-circuit of the timer time setting capacitor (not shown) is released, and the short-time energization timer TM ₁ switches SW as shown in FIG. 6C. A gate signal is given to thyristor Q ₁ through capacitor C ₁ for T ₁ hour after switching to the NO side of ₁ ,
Thereby, thyristor Q ₁ conducts for T ₁ hour as shown in FIG _{. 6D, and therefore relay RY 2 is} energized for T ₁ hour as shown in _FIG . Only the signal line A ₃ switches to the NO side,
The voltage between A _{and 4} is reduced to zero for ₁ hour (lights out signal), and the regular lighting circuit _Vb of the emergency lighting equipment is switched to the 6th
As shown in FIG. F, the lighting state is switched to the off state, the capacitor (not shown) for setting the timer time of the long-time energization timer TM ₂ is short-circuited, and the power supply to the long-term energization timer TM ₂ is stopped.

Furthermore, when switch SW ₁ is switched from the NO side to the NC side at time t ₂ , the energization to the relay RY ₃ is stopped and the contacts ry _3a , ry _3b , and ry _3c are switched from the NO side to the NC side.
The long-time energization timer TM ₂ for lighting is energized and the short-circuit of the timer time setting capacitor is released, and after the long-time energization timer TM ₂ is switched to the NC side of the switch SW ₁ as shown in Figure 6G. A gating signal is applied to thyristor Q ₁ via capacitor C ₁ for T ₂ hours (T ₂ > T ₁ ), which causes thyristor Q ₁ to conduct for T ₂ hours and thus to relay RY ₂ for T ₂ hours. is energized, contact ry ₂ switches to the NO side for T ₂ hours, the voltage between signal lines A ₃ and A ₄ becomes zero voltage (lighting signal) for T ₂ hours, and the normal lighting circuit V of the emergency lighting equipment is switched on. _b is switched from the off state to the on state, the capacitor for setting the timer time of the short-time energization timer _TM1 is shorted, and the power supply to the short-time energization timer _TM1 is stopped.

On the other hand, if you turn off the batch lighting switch SW ₂ ,
The power to relay RY ₄ , which is in the self-holding state, is stopped, contacts ry _4a , ry _4b , ry _4c , and ry _4d switch from the NO side to the NC side, and switch SW ₁ switches to the NO (lights out) side. In some cases, long-time energization timer
When TM ₂ is energized, the short circuit of the timer time setting capacitor is released, and the long-time energization timer is activated.
Based on the operation of TM ₂ , the regular lighting circuit V _b of the emergency lighting equipment is switched from the off state to the on state, and the pilot lamps RL ₁ are energized to indicate that they are all turned on.

By opening the locking lighting interlocking contact _S1 ,
When the switch SW ₁ is switched to the NO side, the regular lighting circuit V _b of the emergency lighting equipment can be turned on in the same way as when the switch SW ₁ is switched to the NC side. In addition, automatic fire alarm equipment transfer contact S ₂
By opening them, a batch lighting operation can be performed.

In addition, SW ₃ is a reset type switch for self-holding the relay RY ₄ , F is a fuse, PL ₂ is a pilot lamp for indicating energization, and TR ₁ is a power transformer.

As shown in Figure 3, when the switchboard is supplied with voltage from the switching signal generation circuit via signal lines A ₃ and A ₄ (at all times), relay RY ₅ is energized by this voltage. Contacts ry _5a and ry _5b have been switched to the NO side, so the magnetic contactor MC is energized, contacts MC ₁ and MC ₂ are closed, and the commercial power supply is connected between power lines A ₅ and A _6. A voltage is generated and the charging circuit V _a
and the switching circuit, and power is also supplied to the regular lighting circuit V _b via the contact ry ₁ of the relay RY ₁ to turn it on.

Also, when a lighting signal or a lighting signal is given from the switching signal generation circuit, relay RY ₅ is not energized.
Stop for T ₁ hour or T ₂ hours and close contacts ry _5a , ry _5b
is switched to the NC side during that time, and therefore the energization to the magnetic contactor MC is also stopped for T ₁ hour or T ₂ hours, and contacts MC ₁ and MC ₂ are opened during that time.
There is zero voltage between power lines A ₅ and A ₆ , and the zero voltage time is
When T ₁ (light off signal), the contact is turned on by the switching circuit.
ry ₁ switches to the NC side and switches the regular lighting circuit V _b from the lighting state to the lights-out state, and when the zero voltage time is T ₂ (lighting signal), the switching circuit turns the contact ry ₁ on.
Switch to NO side and switch from off state to on state. When the contact ry _5a switches to the NC side, the power outage compensation timer TM ₃ with the timer time T ₃ (T ₃ > T ₂ > T ₁ ) starts operating, but the timer TM 3 is given from the signal lines A ₃ and A ₄ . If the signal is a normal light-off signal or light-on signal, contacts ry _5a and ry _5b switch to the NO side before the power failure compensation timer TM ₃ times up, and the power failure compensation timer TM ₃ does not time up.

Furthermore, if the commercial power supply is normal but the signals given from the signal lines A ₃ and A ₄ are abnormal signals, that is, if the zero voltage time is long, the power failure compensation timer TM ₃ times up and the signal is Line A ₃ ,
After time T ₃ has elapsed from the time when the voltage across A ₄ becomes zero, a gate signal is applied to thyristor Q ₂ via resistor R ₁ , which makes thyristor Q ₂ conductive and therefore energizes relay RY _6. contact ry ₆ switches from the NC side to the NO side, the magnetic contactor MC is energized, contacts MC ₁ and MC ₂ are closed, a voltage is generated between the power lines A ₅ and A ₆ , and the charging circuit V Restart the power supply to _a and the switching circuit to prevent the emergency lighting equipment from turning on, and then switch the contact ry ₁ of relay RY ₁ to the NO side using the switching circuit to restart the power supply to the regular lighting circuit V _b . Lights up.

As shown in Figure 4, in the switching circuit, when contacts MC ₁ and MC ₂ of the electromagnetic contactor MC on the distribution board are closed, current flows in the direction of the arrow y in the switch element (PUT) Q ₃ and the anode・As the current flows between the cathodes, current flows to the gate of thyristor Q ₄ , relay RY ₁ operates and its contact RY ₁ becomes NO.
The commercial power supply' is connected to the regular lighting circuit _Vb , and the fluorescent lamp 13 is turned on. At this time, the capacitor _C2 is charged, and when the charging voltage of the capacitor _C2 exceeds a predetermined value, the switch element _Q3 is cut off, but the thyristor _Q4 is maintained in a conductive state by the capacitor _C3 . Next, contact MC ₁ ,
When MC ₂ is opened, the charge stored in capacitor C ₂ is discharged through resistor R ₂ and the capacitor is
The voltage on C ₂ gradually drops. At this time, thyristor Q ₁ shuts off once, excitation of relay RY ₁ stops, contact ry ₁ switches to the NC side, and the commercial power supply is switched off.
The power supply to the regular lighting circuit V _b is stopped, and the regular lighting circuit V _b enters the light-off state. When contacts MC ₁ and MC ₂ are opened again after about ₂ hours T, the potential at point b is lower than the potential at point a because the amount of discharge of capacitor C ₂ is large, and switch element Q ₃ becomes conductive again. Thyristor Q ₄ becomes conductive, relay RY ₁ operates, and contact ry ₁ switches to the NO side, so that the regular lighting circuit V _b returns to the lighting state. Also, the contact
If the opening time of MC ₁ and MC ₂ is about T ₁ hour,
The amount of discharge of capacitor C ₂ is small and the potential at point b is a
Since the potential is higher than that at the point, the switch element _Q3 remains in the cut-off state, and therefore the thyristor _Q4 also remains in the off state. Therefore, the relay RY ₁ is not energized and the contact ry ₁ remains switched to the NC side, and the regular lighting circuit V _b is disconnected from the commercial power supply' and turns off. In this way, relay RY ₁ of the switching circuit is operated by opening and closing contacts MC ₁ and MC ₂ by the signal from the switching signal generation circuit, and the contact
By ry ₁ , only the power supply to the regular lighting circuit V _b can be interrupted. Note that R ₃ to R ₁₂ are resistors, DB ₁ is a bridge rectifier, D ₁ and D ₂ are diodes, and PL ₃ is a pilot lamp.

As shown in Fig. 5, the emergency lighting equipment has a charging circuit V _a and a regular lighting circuit V _b that are constantly supplied with power from the commercial power supply', and a storage battery 9 of the charging circuit V _a that supplies power during a power outage of the commercial power supply'. Regular lighting circuit
It consists of a transistor inverter V _c that turns on the fluorescent lamp 13 of V _b in an emergency, and by switching contact ry ₁ , the power supply to the charging circuit V _a continues at all times and the power supply to the normal lighting circuit V _b is cut off. I am now able to connect with you.

To explain in more detail, when the commercial power source is normal, the storage battery 9 is charged via the power transformer 5, bridge rectifier 6, and charging resistor 7, and the voltage between the power lines _A5 and _A6 causes a power outage. Detection relay 10 is energized and relay contacts 10a, 10
Turn b and 10c to the NO side, and connect commercial power '→contact
MC ₂ → Power line A ₆ → Contact ry ₁ → Terminal X ₁ → Chiyoke coil 12 → Relay contact 10a → Fluorescent lamp 13 →
Relay contact 10b → parallel circuit of glow starter 14 and noise prevention capacitor 14' → fluorescent lamp 13 → inspection switch 15 → terminal X ₂ → power line A ₅ →
Contact MC ₁ → Fluorescent lamp 13 in the commercial power supply route
Start the commercial power supply′ → Contact MC ₂ → Power line A ₆ →
Contact ry ₁ → terminal X ₁ → check coil 12 → relay contact 10a → fluorescent lamp 13 → inspection switch 15
_{→ terminal _}

On the other hand, when the commercial power supply ' is out of power, charging of the storage battery 9 is stopped, and excitation of the power outage detection relay 10 is also stopped, and the relay contacts 10a, 10b, and 10c are closed.
It falls to the NC side, and power is supplied from the storage battery 9 to the transistor inverter V _c through the relay contact 10 c, and the transistor inverter V _c starts high-frequency oscillation, and this high-frequency oscillation output causes the relay contact 10 to
The fluorescent lamp 13 is turned on in an emergency through the terminals a and 10b.

However, in such a configuration, when the switch SW ₁ of the switching signal generation circuit is switched to the NC side and the regular lighting circuit V _b is in the lighting state,
As shown in Fig. 7A, when switch SW ₁ is repeatedly switched several times in a short period of time and switched to the NC side and then stopped, relay RY ₃ is also switched to Fig. 7B.
As shown in FIG. 7, the current is applied in response to the switching of the switch SW ₁ , and at the beginning of the switching operation of the switch SW ₁ , the short-time energization timer TM ₁ for turning off the light operates, and a gate signal as shown in FIG. 7C is output to the thyristor Q. given to ₁ ,
As a result, the thyristor Q ₁ becomes conductive as shown in FIG. 7D, and therefore the relay RY ₂ is energized as shown in FIG. 7E, and the contact RY ₂ switches to the NO side.
There was a problem in that the regular lighting circuit _Vb was switched to the off state during this period (malfunction) as shown in FIG. 7F.

Note that the switching operation of the switch SW ₁ for a short period of time is, for example, when the switch SW ₁ is accidentally switched to the NO side while the light is on, and then immediately returned to the NC side. .

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a switching signal generating circuit that can prevent malfunctions caused by repeated switching operations within a short period of time as described above.

An embodiment of the present invention will be described based on FIGS. 8 to 11. As shown in Figure 8, this switching signal generation circuit' switches contact ry 1 to the normally closed side in response to a short-term power supply suspension, and switches contact ry ₁ to the normally closed side in response to a long-term power supply _suspension . It controls the switching circuit that switches to the open side, and includes switch SW ₁ and a short-time energization timer that selectively operates in response to the switching operation of switch SW ₁ .
Power is supplied to the switching circuit through TM ₁ and long-time energization timer TM ₂ and COM-NC of its own contact ry ₂ , and the short-time energization timer TM ₁ or long-time energization timer TM ₂ is driven during the timer operation period. relay RY ₂ that switches contact RY ₂ to the normally open side, and a light-off signal delay that interrupts transmission of the short-time energization timer selection operation of switch SW ₁ to the short-time energization timer TM ₁ that is repeated within a short time. When the switch SW ₁ is switched from the NC side to the NO side, the turn-off signal generated between the signal lines A ₃ and _{A 4} is processed by the turn-off signal delay timer TM ₄ for T ₄ hours (T _Four
＞T ₂ ＞T ₁ ). To explain in more detail, the illustrated state is a lighting state, and switch SW ₁ is in the NC state as shown in FIG. 10A.
Figure 10B switches to relay RY ₇ .
As shown in the figure, it stops and contact ry ₇ switches to the NC side, and power is constantly supplied to timer TM ₄ for delaying the light-off signal, and the capacitor (not shown) for setting the timer time is short-circuited by contact ry ₇ . Then, a gate signal as shown in FIG. 10C is applied from the turn-off signal delay timer TM ₄ to the thyristor Q ₅ via the capacitor C ₄ , thereby making the thyristor Q ₅ conductive as shown in FIG. 10D. , so relay RY ₈ is energized and the contacts are closed as shown in Figure 10E.
ry ₈ switches to the NO side, relay RY ₃ is energized and contacts ry _3a , ry _3b , ry _3c are connected as shown in Fig. 10F.
switches to the NO side, the short-time energization timer TM ₁ does not generate a gate signal as shown in Figure 10G, and the thyristor Q ₁ is cut off and relay RY ₂ is energized as shown in Figure 10H. stops, contact ry ₂ switches to the NC side, and contact ry ₁ of relay RY ₁ is switched from the commercial power supply' to the NC side.
A voltage is constantly generated between the signal lines A ₅ and A ₆ via COM and NC, and the regular lighting circuit V _b is in a lighting state.

In this state, switch SW ₁ is
As shown in Figure 10, when switching from the NC (on) side to the NO (lights off) side at time t ₁ , relay RY ₇ is energized as shown in Figure 10B, contact RY ₇ is switched to the NO side, and the lights off signal is output. The short-circuit of the timer time setting capacitor of the delay timer TM ₄ is released, the light-off signal delay timer TM ₄ starts its timer operation, and ₄ hours after the switch SW ₁ is switched to the NO side, the timer reaches the 10th timer. The generation of the gate signal is stopped as shown in Figure C, which causes thyristor Q ₅ to shut off as shown in Figure 10D, and therefore the energization of relay RY ₈ is stopped as shown in Figure 10E. and contact
ry ₈ switches from the NO side to the NC side, and as shown in Figure 10F, the current to relay RY ₃ is stopped and the contact is closed.
ry _3a , ry _3b , ry _3c switch from NO side to NC side,
After the switch SW ₁ is switched to the NO (lights off) side, the short-time energization timer TM ₁ for turning off the light is energized with a delay of ₄ hours, and the short circuit of the timer time setting capacitor is released, and the contacts ry _3a , ry _3b , ry T ₁ after switching to NC side of _3c
Short-time energization timer TM ₁ to capacitor
A gating signal is applied to thyristor Q ₁ via C ₁ as shown in FIG. 10G, which causes thyristor Q ₁ to conduct for a time T ₁ and thus
As shown in Figure 10H, RY ₂ is energized for T ₁ hour and contact RY ₂ switches to the NO side for T ₁ hour.
The voltage between signal lines A ₅ and A ₆ is reduced to zero voltage for T ₁ hour (lights off signal), and the normal lighting circuit of the emergency lighting equipment is switched on.
V _b is switched from the lit state to the off state, the capacitor for setting the timer time of the long-time energization timer TM ₂ is shorted, and the power supply to the long-term energization timer TM ₂ is stopped.

In addition, when switch SW ₁ is switched from the NO side to the NC side at time t ₂ , the power to relay RY ₇ is stopped, contact RY ₇ is switched to the NC side, and the timer for delaying the lights-out signal is activated.
Short-circuit the capacitor for setting the timer time of TM ₄ ,
A gate signal is immediately given to thyristor Q ₅ from timer TM ₄ for delaying the light-off signal, and the thyristor
Q ₅ conducts, relay RY ₈ is energized, and contact ry ₈ is closed.
Switches to NO side, relay RY ₃ is energized and contacts
ry _3a , ry _3b , and ry _3c are switched to the NO side, and the long-time energization timer TM ₂ for lighting is energized, and the short-circuit of the capacitor for setting the timer time is released, and the long-time energization timer TM ₂ is switched to the NO side. As shown in Figure 10 _, T ₂ hours (T ₂ >
A gate signal is given to thyristor Q ₁ through capacitor C ₁ by T ₁ ), which causes the thyristor to
Q ₁ conducts for T ₂ hours and therefore relay RY ₂
contact ry ₂ is energized for only T ₂ hours _.
Switches to the NO side, reducing the voltage between signal lines A ₃ and A ₄ to T ₂
The voltage is set to zero (lighting signal) for a certain period of time, the regular lighting circuit V _b of the emergency lighting equipment is switched from the off state to the on state, the capacitor for setting the timer time of the short-time energization timer TM ₁ is short-circuited, and the short-time energization timer is Stop power supply to TM ₁ .

Other configurations and operations are similar to those in FIG. 2.

In this embodiment, the light off signal is switched to NO of switch _SW1 .
Since the output is delayed by T ₄ hours from the side switching operation, that is, after switch SW ₁ switches to the NO side as shown in FIG. 10A, T ₄ as shown in FIG. 10C. After a time delay, the timer TM ₄ for delaying the light-off signal times up, and as a result, the short-time energization timer TM ₁ generates a gate signal to the thyristor Q ₁ as shown in FIG. _10G . When switching to the NC (lighting) side and the regular lighting circuit V _b is in the lighting state, the switching operation of switch SW ₁ is repeated several times within a short period of time as in period K ₁ in Fig. 11A. When the switch is switched to the NC side and then stopped, the energization to the relay RY ₇ is interrupted accordingly, but the timer TM ₄ for extinguishing time delay does not time up as shown in FIG. 11B. The gate signal to thyristor _Q5 remains output,
The operation of switch SW ₁ is not transmitted to relay RY ₃ ,
Short-time energization timer TM ₁ does not operate and does not output a gate signal to thyristor Q ₁ . On the other hand, the first
After time t ₃ in Figure 1 A, switch SW ₁ is continuously turned to NO.
As shown in Figure 11B, when _T4 hours have elapsed from time _t3 , the timer for delaying the lights-out time is activated.
T ₄ times up and the gate signal to thyristor Q ₅ disappears. From this point on, the operation of switch SW ₁ is transmitted to relay RY ₃ and the short-time energization timer is activated.
TM ₁ is activated and outputs a gate signal to thyristor Q ₁ for a time T ₁ as shown in FIG. 11C.

With this configuration, it is possible to prevent malfunctions in switching when the switch SW ₁ is operated incorrectly, when the locking interlocking contact S ₁ malfunctions, and when the switching operation is erroneously operated.

FIG. 9 shows a specific circuit configuration of the circuit portion of FIG. 8, and corresponding parts are given the same reference numerals. _R13 ～
_R16 is a resistor, and _D3 to _D6 are diodes.

As described above, the switching signal generation circuit of the present invention switches contact ry 1 to the normally closed side in response to a short-term power supply suspension, and switches contact _{ry 1 to} the normally closed side in response to a long power supply suspension. This is a switching signal generation circuit that controls a switching circuit that switches to the side, and includes a switch SW ₁ and a short-time energization timer that selectively operates in response to the switching operation of this switch SW ₁ .
Power is supplied to the switching circuit through TM ₁ and long-time energization timer TM ₂ and COM-NC of its own contact ry ₂ , and the short-time energization timer TM ₁ or long-time energization timer TM ₂ is driven during the timer operation period. relay RY ₂ that switches contact ry ₂ to the normally open side when the switch SW 1 is activated, and a light-off signal delay that interrupts the transmission of the short-time energization timer selection operation of the switch SW ₁ to the short-time energization timer TM ₁ that is repeated within a short time. The set time of the timer _TM4 for delaying _the light-off signal is set longer than the set time of the long- _{time energization timer TM2 .} This has the effect of preventing switching malfunctions (including operational errors, etc.).

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional emergency lighting system.
Figure 2 is a circuit diagram of the switching signal generation circuit, Figure 3 is a circuit diagram of the distribution board, Figure 4 is a circuit diagram of the switching circuit, and Figure 5 is a circuit diagram of the switching signal generation circuit.
The figure is a circuit diagram of the emergency lighting equipment, Figure 6 is a waveform diagram of each part of the switching signal generation circuit, Figure 7 is a waveform diagram of each part of the switching signal generation circuit to explain the shortcomings, and Figure 8 is a waveform diagram of each part of the switching signal generation circuit.
9 is a circuit diagram of a switching signal generating circuit according to an embodiment of the present invention, FIG. 9 is a specific circuit diagram thereof, and FIGS. 10 and 11 are waveform diagrams of various parts thereof. ′...Switching signal generation circuit, SW ₁ ...Switch,
TM ₁ ...Short-time energization timer, TM ₂ ...Long-time energization timer, RY ₂ ...Relay, ry ₂ ...Contact, TM ₄
...Timer for delaying light-off signal, ...Switching circuit,
RY ₁ ...Relay, RY ₁ ...Contact, RY ₃ ...Relay,
ry _3a ...Contact.

Claims (1)

[Claims] 1 A switching signal generation circuit that controls a switching circuit that switches contact RY ₁ to the normally closed side in response to a short-term power supply suspension and switches contact RY ₁ to the normally open side in response to a long-term power supply suspension. There is a switch SW ₁ and a short-time energization timer that selectively operates in response to the switching operation of switch SW ₁ .
Power is supplied to the switching circuit through TM ₁ and long-time energization timer TM ₂ and COM-NC of its own contact ry ₂ , and the short-time energization timer TM ₁ or long-time energization timer TM ₂ is driven during the timer operation period. relay RY ₂ that switches contact ry ₂ to the normally open side when the switch SW 1 is activated, and a light-off signal delay that interrupts the transmission of the short-time energization timer selection operation of the switch SW ₁ to the short-time energization timer TM ₁ that is repeated within a short time. and a timer _TM4 for delaying the light-off signal, the switching signal generation circuit having a set time of the timer _TM4 for delaying the light-off signal set to be longer than a set time of the long-time energization timer _TM2 .