RU21479U1 - REAR FOG LIGHTS RELAY - Google Patents

Description

The rear fog lamp relay is part of the vehicle’s electrical equipment and is designed to turn on the rear fog lamps from a push button switch, depending on the enable signal.

Known relay rear fog lights (certificate of the Russian Federation for utility model No. 15420 MPK N 01 N 47/22 option 2, published in the bulletin No. 28 dated 10.10.2000), containing an electromagnetic relay with protective diodes, a transistor switch, a chip consisting of two D triggers, one of which is used as a counting trigger with a preset circuit, and the other is used as an RS trigger, an inverter on a transistor and two resistors, an input capacitance and a charging resistor, an input circuit consisting of two protective diodes, a current limiting resistor, and a push-button resistor lyuchatelya, voltage regulation and protection diode.

The disadvantage of this rear fog lamp relay is that the signals at the R and S inputs of the trigger change simultaneously, which can lead to an undefined state of the outputs of the R-S trigger, and

R and S inputs also do not have a stable threshold, which leads to a decrease in the noise immunity of the relay.

These shortcomings were eliminated in the rear fog lamp relay (certificate of the Russian Federation for utility model No. 15420 MPK N 01 N 47/22 option 1, published in bulletin No. 28 dated 10.10.2000), due to the use of a trigger instead of an RS, and an inverter on the transistor and two Schmidt trigger resistors in the form of a separate chip and two integrating circuits. The Schmidt trigger has a stable response threshold and has hysteresis, which increases the noise immunity of the relay. But the use of a Schmidt trigger in the relay circuit in the form of a separate microcircuit leads to an increase in the cost of the relay, which is economically disadvantageous.

The proposed utility model allows to reduce the cost of the relay rear fog lights, while maintaining a high level of noise immunity

To do this, in the well-known relay of the rear fog lights, containing, we have an electromagnetic relay; transistor switch; a chip consisting of two D triggers, one of which is a counting trigger with a preset circuit; Schmidt trigger; input circuit; the voltage stabilizer, the aforementioned Schmidt trigger is implemented on the second half of the chip by supplying high-level signal inputs to D, C, R and by connecting two resistors to the S input, the second output of the first resistor connected to the direct output Q, which is connected to the input of the counting trigger, and the second output of the second resistor is connected to a common

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the connection point of the first capacitor and the third resistor, the second output of the first capacitor connected to the common bus of the power source, and the second output of the third resistor connected to the inverter output on the transistor and two resistors, the input of which is connected to the output of the input circuit.

FIG. 1 is a schematic diagram of an electrical circuit diagram of a rear fog lamp relay.

In FIG. 2 are diagrams explaining the principle of operation of the relay.

The rear fog lamp relay contains an electromagnetic relay 1; transistor switch 2; a chip consisting of two D triggers, one of which is used as a counting trigger 3 with a preset circuit consisting of a capacitor 4 and a resistor 5; input circuit 6; voltage stabilizer 7; Schmidt trigger 8, implemented on the second half of the microcircuit and on the first and second resistors 9 and 10 (first, the D trigger turns the usual signal follower 1 through a certain connection of leads, then the repeater turns the Schmidt trigger 2 by connecting the feedback resistor 9 and input resistor 10 ); an integrating circuit on the first capacitor 11 and the third resistor 12; an inverter 13 on a transistor and two resistors. The relay is equipped with terminals 14 for connecting the positive pole of the enable signal, 15 for connecting the positive pole of the power source, 16 for connecting the rear fog lamps.

The relay operates as follows. When the ignition key of the car is turned on, voltage is supplied to terminal 15 of the relay, and after turning on the dipped or main beam headlamps or front fog lights, an enable signal is output to terminal 14 of the relay. In this case, through the stabilizer 7, a countable trigger 3, a Schmidt trigger 8 and an inverter 13 on a transistor and two resistors are powered. The preset circuit of the counting trigger 3 at the time ti generates a reset signal at the input R (in Fig. 2 UR), setting a direct signal at the direct output of the counting trigger 3, which goes to the transistor switch 2. In this case, the transistor switch 2 is closed, the electromagnetic coil relay 1 is de-energized and its contacts are open. The button switch of the input circuit 6 is open and therefore the output of the inverter 13 has a low signal level, which is fed through the resistor 12 to the capacitor 11, while the voltage across the capacitor 11 remains low (in Fig. 2 Uii). After pressing the push-button switch of the input circuit 6 (in Fig. 2 Ue), at time tz the inverter 13 closes and a high level signal appears at its output, which starts to charge the capacitor 11 through the resistor 12. At time ts, when the voltage across the capacitor 11 reaches the operating voltage of the Schmidt trigger 8, determined by the ratio of resistors 9, 10 and the value of the supply voltage 2, the Schmidt trigger 8 is switched and a high level signal is generated at its output (in Fig. 2 Uc), which is fed to the input of the counted

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trigger 3. In this case, at the output Q of the counting trigger 3, a signal appears

high level (in FIG. 2 UG), which puts the transistor switch 2 into saturation mode. The electromagnetic relay 1 is activated and its contacts are closed.

After releasing the push-button switch of the input circuit 6 at the time t4, the output of the inverter 13 sets the signal low and the capacitor 11 starts to discharge through the resistor 12. At the time ts, the voltage across the capacitor 11 reaches the release voltage of the Schmidt trigger 8 and a low level is formed at its output signal. In this case, the counting trigger 3 does not change its state.

When the input circuit 6 button is pressed and released again, the process of charging and discharging the capacitor 11 is repeated and the Schmidt trigger 8 outputs the pulse signal to the input of the counting trigger 3. The leading edge of this pulse at time 1b switches the counting trigger 3, setting the Q level at the output low voltage. The transistor switch 2 is closed, the electromagnetic relay 1 is de-energized and at the same time its contacts open.

List of references:

1. The magazine "Radio 1995. No. 7 (p. 36, 37)

2.Zeldin E.A. Digital integrated circuits in information measuring equipment. - L .: Energoatomizdat, 1986. (p. 198)

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Claims (1)

The rear fog lamp relay, containing an electromagnetic relay, a transistor switch, a chip consisting of two D triggers, one of which is a counting trigger with a preset circuit, a Schmidt trigger, an input circuit, a voltage regulator, characterized in that the said Schmidt trigger is implemented in the second half microcircuits by supplying high-level signals to the D, C, R inputs and by connecting two resistors to the S input, the second output of the first resistor connected to the direct output Q, which is connected to the input of the counted rigger, and the second output of the second resistor is connected to a common connection point of the first capacitor and the third resistor, the second output of the first capacitor connected to the common bus of the power source, and the second output of the third resistor connected to the inverter output on the transistor and two resistors, the input of which is connected to the output input circuit.