CN201298957Y - Staged-dimming control signal control circuit for electronic ballast - Google Patents

Abstract

The utility model relates to a staged-dimming control signal control circuit combined with an electronic ballast driving at least one lamp, which comprises two control switches, two isolation and high-low level shaping circuits, a pair of interlock switches and a controllable digital-to-analog conversion circuit; wherein, the two isolation and high-low level shaping circuits which have the same structure and are independent from each other comprise rectifier diodes, current-limiting resistors, photocouplers, charging resistors and filter capacitors; the interlock switches comprise four switching transistors; and the controllable digital-to-analog conversion circuit is formed by a resistor network. After the photocouplers convert the on-off signals of mechanical switches into the digital signals of a high-low level, the high-low level is converted into a direct-current level by the transistor interlock switches and the resistor network. The utility model is characterized by simple structure and reliable operation.

Description

A kind of sectional dimming electric ballast dimming control signal control circuit

Technical field

The utility model relates to dimming electronic ballast, particularly a kind of dimming control signal control circuit of sectional dimming.

Background technology

At lighting field, in order to save the energy better, the requirement of luminosity of regulating lamp as required is urgent day by day.Fluorescence lamp ﹠ lantern gaseous discharge lamp, because of its impedance is nonlinear characteristic, more more complex than the light modulation of traditional incandescent lamp.Fortunately many semiconductor manufacturing factories have been developed numerous driver ics that is used for electric ballast, as long as import the three ten-day period of hot season spy's of a change low-voltage direct-current control voltage to " brightness adjustment control " pin of these integrated circuits, just can change frequency, duty ratio or other parameters of the drive signal of its output, realize changing the power output of ballast, reach the purpose that changes brightness of fluorescent lamp.

According to producing, transmit and obtaining the different of variable low-voltage direct dimming control signal, dimming ballast has multiple sorting technique.The early stage employing laid two control lines in addition, the brightness adjustment control voltage of a 0-10 volt directly is provided for dimming ballast, also favourable being used in is connected in series a controllable silicon angle of cut-off control device on the supply lines, variation with angle of cut-off is converted to variable direct voltage again, and they often are called as " simulation " dimming mode.On supply lines, formed a kind of industry standard of the X10 of being called agreement, be called as " numeral " light modulation with the carrier wave digitally coded digitally addressed method that superposes.

Whether continuous according to light modulation brightness can be divided into continuous light tuning and sectional dimming two classes.In the sectional dimming, a kind of two phase lines input is arranged, the light modulation scheme of a center line input according to the different switching state of two control switchs that is connected on two phase lines, realizes the brightest of ballast control lamp, the three-stage dimming of intermediate light and dark brightness.

The utility model content

Technical problem of the present invention is to provide a kind of simple segmentation to control the dimming control signal control circuit of lamp brightness.

In order to solve above technical problem, the utility model provides a kind of sectional dimming electric ballast dimming control signal control circuit, the center line N of AC power directly inserts electric ballast, the phase line L of alternating current is divided into L1 line and L2 line two-way input electric ballast through two switch SW 1, SW2; Between the phase line L1 and L2 of AC power center line N and suspension control switch SW1 and SW2 control, meet rectifier diode D1, D2 respectively, current-limiting resistance R1, R2, the light-emitting diode of photoelectrical coupler U1, U2 input; The transistor collector of photoelectrical coupler U1, U2 output is connected together, and R3 meets direct voltage+Vcc through charging resistor; The end ground connection of filtering capacitor C1, C2, the other end respectively with photoelectrical coupler U1, the emitter of U2 output is connected, and with the main switch Q1 of corresponding interlock switch, the base circuit of Q2 and another road auxiliary switch Q3, the collector circuit of Q4 is connected together; The emitter of main switch Q1, Q2 and auxiliary switch Q3, Q4 is ground connection all.

The collector series connection of described main switch Q1 has resistance R a, Rb, Rc and Rd to be connected with DC power supply+Vcc, and constitutes resistor voltage divider network, and wherein, tie point A between Ra and the Rb and the output of the dividing potential drop between the ground are delivered to electric ballast as dim signal.

The collector and emitter of described main switch Q1 is attempted by on the resistance R d; The collector and emitter of main switch Q2 is attempted by on the resistance R d and Rc of polyphone.

Control circuit of the present utility model comprise two-way identical by control switch, rectifier diode, current-limiting resistance, the controlled D/A converting circuit that the switch control that photoelectrical coupler and filtering capacitor are formed, buffer circuit and a pair of interlock switch that is made of four transistors and resistor network are formed.

Ac supply signal is through rectifies, and current-limiting resistance becomes the input that is added to photoelectrical coupler after one way signal and the step-down, when control switch closes, and photoelectrical coupler output conducting, filtering capacitor is charged to high level via charging resistor; When control switch disconnected, the photoelectric coupler output end open circuit was low level on the filtering capacitor.When two way control switch were combined upward, two switching tubes of interlock switch all turn-offed, and D/A converting circuit output maximum level makes lamp that maximum brightness be arranged corresponding to ballast; When one of control switch of double switch control, buffer circuit closes, interlock switch is guaranteed the conducting of one of two switching tubes, what of short-circuit resistance according to by the switching tube conducting time, D/A converting circuit output is lower than two varying levels of maximum level, corresponds respectively to ballast and makes lamp that intermediate light and dark brightness be arranged; When two way control switch all turn-offed, the power supply of ballast was cut off, and ballast is not worked, and fluorescent tube extinguishes.

Superior effect of the present utility model is: compare with adopting microprocessor or integrates count circuit generation three-stage dimming signal, the utility model adopts the method for separating transistor formation interlock switch more simple and economical.

Description of drawings

Fig. 1 is a basic circuit diagram of the present utility model.

Each sequence number is expressed as respectively among the figure:

SW1, SW2-control switch

D1, D2-rectifier diode

R1, R2-current-limiting resistance

U1, U2-photoelectrical coupler

R3-charging resistor

C1, C2-filtering capacitor

Q3, Q4-auxiliary switch

Q1, Q2-main switch

Ra, Rb, Rc, Rd-digital-to-analogue conversion resistance

Embodiment

See also shown in the accompanying drawing, the utility model will be further described.

As shown in Figure 1, the center line N of AC power directly imports electric ballast, the phase line L of AC power is divided into L1 line and L2 line two-way input electric ballast behind two control switch SW1 and SW2, as long as one of SW1 or SW2 connect, electric ballast can both obtain the power supply supply and operate as normal.

Between the phase line L1 and L2 of AC power center line N and suspension control switch SW1 and SW2 control, meet rectifier diode D1 respectively, D2, current-limiting resistance R1, R2, photoelectrical coupler U1, the light-emitting diode of U2 input.Photoelectrical coupler U1, the transistor collector of U2 output is connected together, and R3 meets direct voltage+Vcc through charging resistor.The end of filtering capacitor C1 and C2 and being connected together of DC power supply publicly, the other end respectively with photoelectrical coupler U1, the emitter of U2 output is connected, and with the main switch Q1 of corresponding interlock switch, the base circuit of Q2 and another road auxiliary switch Q3, the collector circuit of Q4 is connected together.Constitute four transistor Q1 of interlock switch, Q2, the emitter of Q3 and Q4 also with being connected together of DC power supply publicly.The collector and emitter of switching tube Q1 is attempted by on the resistance R d, and the collector and emitter of switching tube Q2 is attempted by on the resistance R d and Rc of polyphone.Resistance R a, Rb, Rc and Rd are connected in series between DC power supply+Vcc and the public ground, constitute a resistor voltage divider network.Deliver to the inverter control circuit of electric ballast, the luminosity of control lamp from the branch pressure voltage exported between the tie point A of resistance R a and Rb and the public ground as dim signal.

When control switch SW1 and SW2 all connect, the output transistor of photoelectrical coupler U1 and U2 is all conductings also, all high level on filtering capacitor C1 and the C2, this makes two auxiliary switch Q3 and all conductings of Q4 of interlock switch, thereby two main switch Q1 of interlock switch and Q2 end, the output voltage that A is ordered is resistance R a and Rb+Rc+Rd dividing potential drop, and output level is the highest.

When control switch SW1 connection, when SW2 disconnected, the output transistor conducting of photoelectrical coupler U1 was high level on the filtering capacitor C1; The output transistor of photoelectrical coupler U2 ends, and is low level on the filtering capacitor C2, the main switch Q1 conducting of interlock switch, and Q2 ends, and the output voltage that A is ordered is resistance R a and Rb+Rc dividing potential drop, and the output voltage that A is ordered is a medium level.

When control switch SW2 connection, when SW1 disconnected, the output transistor conducting of photoelectrical coupler U2 was high level on the filtering capacitor C2; The output transistor of photoelectrical coupler U1 ends, and is low level on the filtering capacitor C1, the main switch Q2 conducting of interlock switch, and Q1 ends, and the output voltage that A is ordered is resistance R a and Rb dividing potential drop, and the output voltage that A is ordered is a minimum level.

When control switch SW1 and SW2 disconnected, the power supply of ballast was cut off, and ballast is not worked, and lamp does not work.

Claims (3)

1, a kind of sectional dimming electric ballast dimming control signal control circuit is characterized in that:

The center line N of AC power directly inserts electric ballast, and the phase line L of alternating current is divided into L1 line and L2 line two-way input electric ballast through two switch SW 1, SW2; Between the phase line L1 and L2 of AC power center line N and suspension control switch SW1 and SW2 control, meet rectifier diode D1, D2 respectively, current-limiting resistance R1, R2, the light-emitting diode of photoelectrical coupler U1, U2 input; The transistor collector of photoelectrical coupler U1, U2 output is connected together, and R3 meets direct voltage+Vcc through charging resistor; The end ground connection of filtering capacitor C1, C2, the other end respectively with photoelectrical coupler U1, the emitter of U2 output is connected, and with the main switch Q1 of corresponding interlock switch, the base circuit of Q2 and another road auxiliary switch Q3, the collector circuit of Q4 is connected together; The emitter of main switch Q1, Q2 and auxiliary switch Q3, Q4 is ground connection all.

2, sectional dimming electric ballast dimming control signal control circuit according to claim 1 is characterized in that:

The collector series connection of described main switch Q1 has resistance R a, Rb, Rc and Rd to be connected with DC power supply+Vcc, and constitutes resistor voltage divider network, and wherein, tie point A between Ra and the Rb and the output of the dividing potential drop between the ground are delivered to electric ballast as dim signal.

3, sectional dimming electric ballast dimming control signal control circuit according to claim 1 and 2 is characterized in that:

The collector and emitter of described main switch Q1 is attempted by on the resistance R d; The collector and emitter of main switch Q2 is attempted by on the resistance R d and Rc of polyphone.