JP3041370B2 - Periodical change device for lamp polarity of DC fluorescent lighting system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for switching the polarity of a DC power signal before operating a fluorescent lamp of a DC lighting device, that is, a device for changing the cycle of the lamp polarity of a DC fluorescent lighting device.

Conventional fluorescent lighting devices can be operated from either AC or DC power. However, when AC power is applied to a fluorescent lamp, the AC signal causes the light provided by the fluorescent lamp to flicker. The flickering effect of light over a certain period of time causes damage to human eyes. Conventional DC fluorescent lighting devices solve this problem by applying a constant signal to the fluorescent lamp, thereby continuously driving the fluorescent lamp. Since the drive signal is not AC, there is no flicker of light provided by the fluorescent lamp. Despite the great advantages of DC fluorescent lighting, significant problems exist. Severe aging and deterioration of the cathode occurs when the fluorescent lamp is driven by direct current in the same direction. Providing a device for switching the polarity of a DC power signal applied to a fluorescent lamp without causing flickering of the light is a great advantage. Such a device prevents premature aging of the lamp cathode.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus for changing the cycle of the lamp polarity of a DC fluorescent lighting device which can selectively switch the polarity of a DC power signal applied to the fluorescent lamp at each time power is applied to the fluorescent lamp. To provide.

It is another object of the present invention to provide an apparatus for changing the polarity of a lamp of a DC fluorescent lighting device in which the polarity of a DC power signal can be periodically switched by an electric circuit means.

According to embodiments of the present invention, the above-mentioned objects, features and advantages of the present invention can be achieved by an apparatus for arbitrarily setting the polarity of a DC power signal to be added to a lamp, the apparatus converting an AC power signal to a lamp. A power supply for changing to a regulated DC power signal that can be driven; switch means connected to the power supply for selectively inverting the polarity of the DC power signal each time the AC power signal is added; A polarity control means for arbitrarily selecting the polarity of the power signal and connected to the switch means for controlling the switch means in accordance with the arbitrary selection; and a DC power signal having a polarity selected by the polarity control means. And an electric lamp to which power is supplied continuously.

Next, an embodiment shown in the accompanying drawings will be described in detail for a device for changing the period of the lamp polarity of the DC fluorescent lighting device of the present invention.

As shown in FIG. 1, the input terminals 80 and 90 are connected to a power supply 101, and the power supply 101 is connected to a switching circuit 102 and a lamp 103 in parallel. Polarity control circuit 104 also has input terminal 80
And 90 in parallel, the polarity control circuit 104 being operative to selectively drive the switching circuit 102 each time an AC power signal is first applied to the input terminals 80 and 90. In operation, when an AC input signal is first applied to terminals 80 and 90, the likelihood that the input signal is to a negative electrode and to a positive electrode is the same. Input terminal 80
When the signal initially applied to the lamps 90 and 90 has a positive polarity, the polarity control circuit 104 operates the switching circuit 102 to reverse the polarity of the DC input signal applied to the lamp 103.

This is very clearly shown with respect to FIG. 2, which shows a circuit diagram of both the polarity control circuit 104 and the switching circuit 102. As shown in FIG. 2, the polarity control circuit 104 has two relay coils 200 and 300, and each relay coil 200 and 300
Is protected by diodes 130 and 140. The relay coil 200 is connected in series with the diode 110 and the relay contact 301, and the diode 110 and the relay contact 301 are connected to the relay coil.
Activated by 300. A relay coil 200 connected in series,
Diode 110 and relay contact 301 are connected in parallel to input terminals 80 and 90, relay coil 300 is connected in series with diode 120 and relay contact 201, and diode 120 and relay contact 201 are operated by relay coil 200. These three
Two series-connected relay coils 300 and a diode 120,
Relay contact 201 is connected to input terminals 80 and 90 in parallel. Relay coil 400 is connected in series with relay contact 202, which is a normally open relay contact operated by relay coil 200. These two components, namely
Relay coil 400 and relay contact 202 are connected in parallel with input terminals 80 and 90. In operation, an AC input signal is applied to input terminals 80 and 90. When the AC input signal is positive, current flows through normally closed relay contact 301 and diode 11 to excite relay coil 200, thereby opening normally closed relay contact 201 and opening normal relay contact 202. Close. When this happens the relay coil 300
Is removed from the circuit, and the current flowing through the contact 202 activates the relay coil 400. Relay coil 300
Is removed from the circuit, relay coil 200 continues to activate relay contact 201 and relay contact 202, thereby activating relay coil 400. The relay coil 400 operates the relay contacts 401 to 404 of the switching circuit 102. When relay coil 400 is actuated, normally open relay contacts 401 and 404 close and normally closed relay contacts 402 and 403
Opens. Therefore, since the adjusted DC input signal passes through the switching circuit 102 and supplies power to the lamp 103, its polarity does not change. The polarity of the DC input signal applied to the lamp 103 does not change as long as power is applied to the input terminals 80 and 90 (even if the signals applied to the terminals 80 and 90 are changed). However, when the AC input signal is removed from input terminals 80 and 90 and subsequently added again, it may be added when the input signal is negative. If it is negative, the current will flow through relay coil 300, diode 120 and normally closed relay contacts
Flows through with 201. Excitation of relay coil 300 is contact 30
Release 1 thereby removing relay coil 200 from the circuit. Therefore, the normally open relay contact 202 remains open, and the relay coil 400 cannot operate. Relay coil 400
Is not activated, the normally open relay contacts 401 and 404 of the switching circuit 102 remain open and the normally closed relay contacts 402 and 403 remain closed. In this case, the switching circuit 102 reverses the polarity of the DC input signal applied to the lamp 103. The polarity is that the AC input signal is the input terminal
As long as they are added to 80 and 90 (even if the input signal applied to these terminals is changed), they remain in the opposite state. Obviously, the polarity of the DC input signal applied to the lamp 103 can be changed at each time the AC input signal is applied to terminals 80 and 90. When the AC input signal is added to the terminals 80 and 90, the probability that the DC input signal applied to the lamp 103 is reversed is the same as the probability that the DC input signal applied to the lamp 103 is reversed because the probability that the polarity is opposite to the negative electrode is the same. It is. Over time, this prevents aging and deterioration of the cathode of the fluorescent lamp 103, which would occur if the polarity did not change.

FIG. 3 shows another embodiment of the present invention in which the polarity control circuit 104 and the switching circuit 102 are replaced with a step relay 105. The step relay 105 is a two-pole rotating relay having a pole connected to each of the input terminals 80 and 90. Each time an AC signal is applied to relay coil 500, relay coil 500 switches connection to the next adjacent contact in a stepwise manner. Since those contacts are wired as shown in Appendix 3, each time a DC signal is applied from the power supply 101 to the relay coil 500, the step relay 105 switches the contacts step by step for each set. Changes the polarity of the DC signal added to the lamp 103. In this manner, the step relay 105 can reverse the polarity applied to the lamp 103 at the time of applying the AC signal to the input terminals 80 and 90, thereby preventing premature aging and deterioration of the lamp cathode.

FIG. 4 shows a simple modification of the step relay 105 in which the manual operation switch 107 is incorporated. The manual operation switch 107 is configured so that an operator can manually operate the relay coil 500. Manual operation switch 10
7 has two poles and contacts, which are easily constructed.
With the manually operated switch 107, the operator simply activates the switch 107 each time the fluorescent lighting device is activated.

FIG. 5 shows a switching circuit 10 for achieving the purpose.
2 shows another embodiment of the present invention using a timing circuit 700. The input terminals 80 and 90 are connected in parallel with a switching circuit 102 through a power supply 101. The switching circuit 102 includes a pair of normally open relay contacts 601 and 604 wired in a cross-coupled manner with the normally closed relay contacts 602 and 603. The switching circuit 102 is connected in parallel with the lamp 103. The timing circuit 700 includes a timing signal generator 701 and a normally closed relay contact 702.
Relay contact 702 is a relay coil 6 between input terminals 80 and 90.
00 and connected in series. Timing signal generator 701
Is connected between the relay contact 702 of the timing circuit and the relay coil 600 through the normally open relay contact 605. The timing signal generator 701 is also connected to the input terminal 90. In operation, an AC input signal is applied to input terminals 80 and 90. The AC input signal drives a relay coil 600 that operates to close relay contact 605. The AC power signal is applied to the timing signal generator 701 through the relay contact 702 and the relay contact 605. When receiving the AC power signal, the timing signal generator 701 counts a preset time before opening the relay contact 702. When relay contact 702 opens, relay coil 600 is removed from the circuit, and contacts 601 and 604 are closed, whereas relay contacts 602 and 603 open, thereby polarity of the DC input signal applied to light 103. The opposite. At the same time, the relay contact 605 opens, thereby interrupting the power transmission of the timing signal generator 701, which prevents the DC power signal from reversing the polarity.

Each of the above-described embodiments of the present invention selects and controls the polarity of a DC signal to be added to the lamp 103 when AC power is added, and sets a period for automatically switching the polarity of the DC power signal. Because of the setting function, the number of hours in which each terminal of the lamp is used as a cathode in long-term use is substantially the same. Therefore, only one terminal is not deteriorated or aged at an early stage. As a result, the lamp 103 can have a long life.

Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the embodiments, and various modifications or changes can be made within the scope of the claims without departing from the scope of the present invention. .

[Brief description of the drawings]

(FIG. 1) FIG. 1 is a block diagram of a device for changing the cycle of the lamp polarity of a fluorescent lighting device according to the present invention. FIG. 2 is a circuit diagram showing an embodiment of the polarity control circuit of FIG. FIG. 3 is a circuit diagram showing an embodiment of a step switching circuit. (FIG. 4) FIG. 4 is a block diagram illustrating a modification of the switching circuit including the manual operation switch. FIG. 5 is a circuit diagram of an apparatus for changing the period of the lamp polarity of a fluorescent lighting apparatus including a timing signal generator and a switching circuit according to another embodiment of the present invention. (Explanation of reference numerals) 80, 90: Input terminal 101: Power supply 102: Switching circuit 103: Light 104: Polarity control circuit 105: Step relay 107: Manual operation switch 700: Timing circuit

Continuation of the front page (56) References JP-A-57-128494 (JP, A) JP-A-57-158995 (JP, A) JP-A-60-30087 (JP, A) JP-A-60-30088 (JP) , A) JP-A-60-39793 (JP, A) JP-A-62-97297 (JP, A) JP-A-44-13654 (JP, Y1) JP-A-45-3143 (JP, Y1) 28-7787 (JP, Y1) Jiko 29-7880 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05B 41/14-41/29

Claims (3)

(57) [Claims] An AC power signal is received, the AC power signal is converted into a regulated DC power signal capable of driving a lamp, and the polarity of the DC power signal is arbitrarily set when the AC power signal is first received. A period changing device of a lamp polarity of a DC fluorescent lighting device for receiving an AC power signal and changing the AC power signal into a DC power signal capable of driving a lamp, The power supply is connected to a switching circuit that receives the DC power signal and reverses the polarity of the DC power signal when the power supply receives the AC power signal, and polarity control for arbitrarily selecting the polarity of the DC power signal A polarity control circuit is connected to the switching circuit to provide a circuit and control the switching circuit according to an arbitrary selection, and the switching circuit has a pole selected by the polarity control circuit. An apparatus for changing the polarity of a lamp of a DC fluorescent lighting device, wherein the lamp is connected to a lamp for lighting with a DC power signal having a characteristic. 2. The method according to claim 1, wherein when the AC signal is first applied to the power supply, the polarity of the DC power signal is selectable by a polarity control circuit in accordance with the initial polarity of the DC signal, and the initial polarity of the AC signal is selected from the positive polarity and the negative polarity. The apparatus according to claim 1, wherein the cycle is changed. 3. A first input terminal and a second input terminal for receiving an AC power signal through a polarity control circuit, a first diode and a second diode, a first relay coil and a normally closed first.
A relay contact, a second relay coil and a normally closed second relay contact, a third relay coil and a normally closed third relay contact, and a normally closed first relay contact, a first relay coil and a first relay coil.
A diode is connected in series between the first and second input terminals, a normally closed second relay contact, a second relay coil, and a second diode are connected in series between the first and second input terminals. A relay contact and a third relay coil are connected in series between the first and second input terminals, and the switching circuit comprises a first input terminal and a second input terminal;
A first output terminal and a second output terminal, and a pair of normally closed contacts and a pair of normally open contacts of a third relay coil;
And a second input terminal connected to the first and second output terminals, respectively, through one of a pair of contacts, and when the AC signal is first applied, the first and second input terminals of the polarity control circuit according to the initial value of the AC signal. The cycle of the lamp polarity according to claim 1, wherein the third relay coil is enabled, and the switching circuit is enabled to switch the polarity of the DC power signal when the third relay coil is operated. Change device.