JPS59266Y2 - Transistor type turn signal/hazard flasher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transistor type turn signal/hazard flasher that improves thermal ribbon type flashers or capacitor type flashers.

The conventionally commonly used thermal ribbon flasher is
Characteristics such as the number of flashes are determined by the current flowing through the thermal ribbon, so for turn signals that flash two lights at the front and rear of the vehicle and hazard lights that flash all four lights on the vehicle, the current is more than double, so parts and adjustments are necessary. The specifications were different, and a single flasher had the disadvantage that it could not be used in common.

The capacitor type flasher also has the disadvantage that it cannot be used as both a turn signal and a hazard, and that the lamp does not light up at the same time as the turn signal switch is turned on, that is, it takes a long time to start lighting.

The purpose of the present invention is to provide a turn signal/hazard flasher that utilizes the charging and discharging of a capacitor and further reduces the withstand voltage and capacity of the capacitor by interposing a transistor to eliminate the above-mentioned drawbacks. Moreover, it is an instant lighting type which is important for traffic safety, and moreover, when one light is broken, the blinking speed is increased so that the breakage can be identified.

An example of an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing the first embodiment of the present invention, in which P
is a normally open relay switch contact, which operates on relay coil L to close it.

C1 is a capacitor which is the basis of the blinking operation in the flasher of the present invention, and the transistor Tr1 is opened and closed by charging and discharging the capacitor C1.

R3 and R6 are discharging and charging resistors respectively arranged in series with the capacitor C1, and R1 is a one-stroke disconnection detection resistor that controls opening and closing of the transistor Tr2.

D2 is a temperature compensation diode.

Furthermore, 2 is a battery, 3 is a lamp, 4 is a turn signal switch, 5 is a ground, and B, L, and E are flasher terminals connected to the battery, lamp, and ground, respectively.

Note that the hazard switch is interposed in this circuit in parallel with the turn signal switch 4, as in the general case.

In the present invention, battery 1 terminal B is connected to battery 2,
Lamp terminal L' to lamp 3, earth terminal E to earth 5
Then, the transistor Tr□ has its emitter connected to the battery terminal B, its collector connected to the ground terminal E via the relay coil L, and its base connected to the ground terminal E via the diode D1, capacitor C1, and resistor R3. Excite and demagnetize the relay coil L.

In addition, the transistor Tr2 has its emitter connected to the battery terminal B via the resistor R1, and its collector connected to the resistor R via the resistor R2.
3 and the capacitor C1, connect the base to the battery terminal B through the forward diode D2 and the resistor R5.
At the same time, it is connected to the connection point a through the variable resistor VR1 and the resistor R4, and the potential of the connection point a is changed to control the ON/OFF time of the transistor Tr1.

Furthermore, a contact P connected to the lamp terminal L' is connected to the connection point a'' between the resistor R1 and the emitter of the transistor Tr2.
The other end is connected to the diode D1 and the capacitor C.
The connection point a' of No. 1 is connected to the lamp terminal L' via a resistor R6.

Note that the diode D1 is a protection diode for the transistor Tr1, and the same effect can be obtained even if a capacitor is connected in parallel between the base and emitter.

Further, the capacitor C2 is a protection capacitor for the transistor Tr1, and the diode D3 is a surge absorption diode.

In addition, the resistor R2 is connected to the connection point a in order to adjust the charging and discharging time.
The resistor R2 may be zero.

Next, the blinking operation of the turn signal will be explained with reference to FIG. 1. When the ignition switch (not shown) is turned on and the turn signal switch 4 is turned to the right or left, the turn signal operates as follows.

Note that since the transistor Tr2 is ON when the turn signal switch 4 is OFF, the capacitor C1
The potential difference between both ends of (potential difference between connection points a and a') is approximately 0
(2), and the transistor Tr1 is OFF.

(1) When the turn signal switch 4 is turned on, the current flows through the path of the current 11 as shown by the thin solid line in Figure 1.
The transistor Tr1 is positively biased and turned on.

(2) When transistor Tr1 turns on, relay coil L
is excited, turning on the contact P, and as shown by the dotted line in Figure 1, the resistance L (micro resistance) and the contact P are connected in the path of the current i2.
, lamp terminal L', and turn signal switch 4, the lamp 3 is energized (lamp 3 turns on).

(3) When the current 12 flows, the transistor Tr2 is reverse biased due to the voltage drop across the resistor R1 (the emitter potential of the transistor Tr2, that is, the potential at the connection point a'' decreases), and the transistor Tr2 is turned OFF.At the same time, the collector potential of the transistor Tr2 is turned off. (The potential at the connection point a) decreases, so a potential difference occurs between both ends of the capacitor C1, and the base current i3 flows along the path shown by the dashed line in FIG. , energizes the ground 5 via the ground terminal E.

Then, the charging current of capacitor C1 (transistor Tr
1 bias current) to maintain the ON state of the transistor Tr1 (01 charging time is lighting time).

(4) When capacitor C1 is fully charged, current i3 stops flowing, and transistor Tr1 and relay coil L
is turned off, and current 12 no longer flows (lamp 3 turns off).

Then, the voltage drop across resistor R□ becomes smaller (connection point a”
Tr2 is turned ON again and the collector potential (potential at the connection point a) rises, so the voltage charged in the capacitor C1 reverse biases the transistor Tr1, so the transistor Tr1 remains OFF. .

(5) The discharge circuit of the capacitor C1 forms a path for the current i4 shown by the two-dot chain line in FIG. Then, the process returns to (1) above (the discharge time of C1 is the light-off time).

Thereafter, steps (1) to (5) are repeated, and the lamp 3 is turned on while the capacitor C1 is being charged, and is turned off and blinked while the capacitor C1 is being discharged.

As can be seen from the above operation, the on/off of the lamp 3 is controlled by the transistors Tr1. Since this is done by charging and discharging the circuit of Tr2, relay coil L, and capacitor C1, transistor Tr2 becomes O
If the resistor R1 is selected so that it becomes an FF (if the potential of the connection point a'' is set), it can also be used as a buzzard flasher, which has a load more than twice that of a turn signal.

Next, the abnormal point reduction operation when one light is disconnected will be explained.

When one lamp 3 is burnt out, the voltage drop across the resistor R1 decreases due to the drop in the current 12 mentioned above, and the transistor Tr
2 becomes difficult to 0FFL (transistor Tr2 operates in class A).

Therefore, the collector potential of the transistor Tr2 (connection point a
The potential of the capacitor C becomes higher than when the transistor Tr2 is OFF, and the charging voltage of the capacitor C (the potential difference between the connection points a and a) becomes lower, so the charging and discharging time of the capacitor C1 becomes shorter and as shown in Fig. 2. Increase the number of blinks as shown.

The first embodiment is a relay coil L and a resistor R of the first embodiment.
A diode D4 is interposed between the lamp terminal L' and the ground terminal E, and a resistor R8 is interposed between the lamp terminal L' and the battery terminal B.

Diode D4 is provided to protect the circuit when external terminals B and E are connected in reverse, that is, when earth terminal E is connected to battery 2 and battery terminal B is connected to earth 5.

If the turn signal switch 4 is turned off while the capacitor C□ is charged, the resistor R8 will not turn on the transistor Tr1 and the lamp 3 will not turn on because the capacitor C1 will be in the charged state even if the turn signal switch 4 is closed next time. In order to prevent this from occurring, a discharge circuit for the capacitor C1 is formed by the resistor R8 in the above case as well.

Therefore, the moment the turn signal switch 4 is closed,
The lamp 3 can be lit at all times.

Next, the second embodiment will be explained. In the second embodiment, a capacitor C3 is connected and intervened between the base and collector of the transistor Tr2 in the circuit of the first embodiment (the third embodiment). Container C is placed in the same position in the example.
(See Figure 6).

This capacitor C3 has the effect of obtaining a stable number of blinks even when a fluctuating voltage due to fluctuations in the power supply is applied to the flasher.

That is, in the first embodiment, when the turn signal switch 4 is closed and the lamp 3 is turned on, if a variable voltage is applied, the emitter potential of the transistor Tr2 (connection point a
” changes, and the bias point of the transistor Tr2 moves.

As a result, the transistor Tr2 amplifies the bias fluctuation, and the potential at the connection point a fluctuates with a larger amplitude than the fluctuation in the potential at the connection point a', so the capacitor C1
The potential difference between both ends of the capacitor C1 is increased compared to the normal state (no fluctuation), and the charging time of the capacitor C1 becomes longer.

In other words, the lighting time becomes longer.

On the other hand, if a capacitor C3 is inserted between the collector and base of the transistor Tr2 in the second embodiment,
Negative feedback is applied to changes in the emitter potential of transistor Tr2 (potential at connection point a'') due to power supply fluctuations, and the potential at connection point a is suppressed from following bias fluctuations, and the lighting time try to keep constant.

When the lamp 3 is turned off, there is no factor contributing to power fluctuations in the discharge path of the capacitor C1, so the amount of charge in the capacitor C1 is discharged in almost the same way as when there is no fluctuation in the power supply, and the turn-off time remains unchanged.

Therefore, capacitor C3 controls the lighting rate due to power supply fluctuations.
It works to keep the number of blinks constant.

Furthermore, since this capacitor C3 has a similar effect on instantaneous noise pulses, it goes without saying that it is also effective in absorbing noise.

Here, the power supply fluctuation (Vp
-p) The results of the characteristic tests accompanying the increase are shown in Figures 3 and 4, and the test conditions were as follows: Test voltage: 12.8V
, load conditions; 12 V/21WX 2 +3.4W (
3,83A at 12.8V), circuit resistance: 0
．． 1±0.01Ω, power supply waveform: The power supply was varied as shown in Figure 5, and the fluctuation frequency f was 100 Hz and 600 Hz, and the ratio of S and C in the figure was b:C21 :
l, is.

The graphs in FIGS. 3 and 4 are for the second embodiment and the first embodiment, respectively.
This is a summary of two examples, and both show the number of blinks and the lighting rate in response to power fluctuations, and the lines d, e, f, and g shown in Figures 3 and 4 respectively. is the state shown in Table 1 below.

In addition, the thicker lines in each state of d, e, f, and g indicate the second embodiment, and the thinner lines indicate the first embodiment.
'An example is shown.

Further, Vp -p = aV is a state without any fluctuation, and the operation stop voltage under normal load is shown in Table 2 below.

In FIG. 3, the upper graph shows the number of blinks when the wire is broken in one stroke, and the lower graph shows the number of blinks when the load is normal.

Here, the variable frequency refers to the frequency of pulsating current (ripple) superimposed on the DC power supply, and is generally used in two-wheeled vehicles and four-wheeled vehicles.
Regardless of whether it's a wheeled vehicle or not, the power supply in an actual vehicle has a simple configuration of an AC generator connected in parallel to a battery via a rectifier, so the rectified waveform cannot be smoothly absorbed, and ripples may be included in the power supply. occurs.

This is called power supply fluctuation Vp-.

Its frequency changes depending on the engine speed.

Therefore, a flashing device that does not cause characteristic changes even with a certain degree of power supply fluctuation Vp- and fluctuation frequency f is practically effective.

Here, based on FIG. 3 and FIG. 4, comparing the characteristics of the second embodiment and the first embodiment with respect to power supply fluctuations, we find that the number of blinks (times/min) and lighting rate (%) under normal load. ), the number of flashes when one light is disconnected (times/min), and the lighting rate (%), the thick line of the second example has a smaller slope than the thinner line of the first example. .

From this, it can be said that in any case, the second embodiment has better characteristics against power supply fluctuations than the first embodiment.

Furthermore, to explain the third embodiment shown in FIG.
In order to improve the load characteristics of the third embodiment compared to the second embodiment, a resistor R1 is inserted between the resistor R3 and the ground terminal E, and the connection point between the resistor R3 and the resistor R1□ is connected to the resistor R9. Connect to battery terminal B via Zener diode ZD
This is because the wires were connected to .

Therefore, the potential of battery terminal B changes when lamp 3 turns on and off (voltage drop due to wiring resistance of the vehicle body, etc.)
The potential difference between the resistor R3 and the battery terminal 3 can be made constant even if the voltage is changed.

This is to keep the potential difference between the connection point a and the connection point a' constant, and to keep the charging/discharging time of the capacitor C1 constant and the number of blinks constant.

Furthermore, by connecting the resistor R9 in series with the Zener diode ZD, the potential of the battery terminal B changes while keeping the potential difference between the resistor R3 and the battery terminal B constant due to the effect of the Zener diode ZD mentioned above. The base potential of the transistor Tr2 is also changed in proportion to this.

This is because the potential of the battery terminal B changes, that is, the emitter potential of the transistor Tr2 (connection point a'') changes,
Preventing the bias point of transistor Tr2 from changing,
- This is to keep the potential difference between both ends of the capacitor C1 constant when the lamp is disconnected, and to keep the number of blinks constant.

Therefore, changes in the number of blinks, lighting rate, etc. due to lamp load are suppressed.

It goes without saying that this method is also effective against voltage changes at the battery terminal B caused not only by the lamp load but also by other factors.

Here, the results of the load characteristic test of the third example and the second example are shown in FIG. 7, and the test conditions were: test voltage: 12.8 V, test temperature: 20±5°C1 Load conditions: about 10 to 200% of the predetermined turn signal load, circuit resistance: 0.10±0.01Ω.

The graph in Figure 7 shows the three types together, and all of them are the number of blinks (times/minute) and
It shows the values of lighting rate (%) and starting time (seconds). In Figure 7, h is the number of blinks (times/minute), i is lighting rate (%),
j indicates the starting time (seconds).

In addition, the thicker lines of h, i, and j indicate the third embodiment, and h
.

The thinner lines i and j indicate the second embodiment.

Here, when the load characteristics of the third embodiment and the second embodiment are compared based on FIG. 7, the graph of the third embodiment shows that, in particular,
The lamp load is flat between 50 and 100W,
Even if the load increases, the lighting rate, the number of blinks, and the starting time hardly change, so it can be seen that the load characteristics are superior when compared with those of the second embodiment.

As detailed above, the present invention is a dual-purpose flasher, which reduces the number of product models and allows for mass production, which is economical. It also has a great effect on traffic safety because it can be pressed to turn on the lamp at the same time as the switch is turned on.

Furthermore, in a condenser type flasher, the capacitor is charged and discharged directly to the operating coil that opens and closes the contacts.
In the present invention, since this is done through two transistors, the withstand voltage and capacitance of the capacitor can be small, and there are advantages in terms of characteristics such as improvement in power supply fluctuation characteristics (noise absorption) and improvement in load characteristics (voltage characteristics).

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of the first embodiment of the present invention, Fig. 2 is a time-potential diagram during normal load and abnormal load, and Fig. 3 is a circuit diagram of the first embodiment of the present invention.
FIG. 4 is a power supply fluctuation vs. blinking frequency diagram comparing the example and the second example, FIG. A test power supply fluctuation diagram for a characteristic change test due to an increase in power supply fluctuations, Figure 6 is a circuit diagram of the third embodiment of the present invention, and Figure 7 is a lamp load comparing the second and third embodiments. It is a diagram of the number of blinks, lighting rate, and starting time. The symbols in the figure indicate the following elements: P: contact, L: relay coil, C1, C2, C3: capacitor, Trl. Tr2: Transistor, Ro, R2, R3, R4, R5
, R6゜R7, R8, R9,'R1o, R1□: Resistance,
Dl, D2. D3゜D4: Diode, ZD: Zener diode, ■R: Variable resistor, 2: Battery, 3: Lamp, 4: Turn signal switch, 5: Ground.

Claims (1)

[Scope of utility model registration request] Transistor T whose emitter is connected to battery terminal B
Connect the collector of r1 to ground terminal E via relay coil L.
The base of the transistor Tr1 is connected to the earth terminal E via the diode D1, the capacitor C1, and the resistor &.
The collector of the transistor Tr2 is connected to the connection point a between the capacitor and the resistor R3 via the resistor R2, the emitter of the transistor Tr2 is connected to the battery terminal B via the resistor R1, and the diode A connection point a' between D1 and the capacitor C1 is connected to the lamp terminal [ via a resistor R6, and a connection point a'' between the emitter of the transistor Tr2 and the resistor R□ is connected to the lamp terminal L' via a contact P. Transistor-type turn signal/hazard flasher-0, which is characterized by being connected.