Momentary Contact Relay Circuit

Solder a wire from pin 87 of the first relay.

Momentary contact relay circuit.

The built in enclosure protects contacts from dust and dirt. This is the output wire positive out. This feature is often required in automotive devices. Solder a wire onto pin 87 of the first relay and connect it to the input pin in step 1.

Now if we start by assuming the internal relay switch is closed on the pink side when the momentary switch is pressed thyristor 2 has a voltage applied to its gate and the blue coil is put in circuit. This circuit allows an spst momentary pushbutton to act as a push on push off switch using a dpdt latching bi stable relay. Solder these relays to a printed circuit board. The resistor bleeds off the charge of the capacitor when positive voltage is removed from the other side of the coil.

An infrared light beam senses the lightest finger contact to switch a circuit on or off. Based on ne555 this circuit turns on and off the ic output by a momentary switch. Choose from our selection of momentary switches including panel mount push button switches toggle switches and more. But the relay coil is not activated until sufficient current is actually flowing through it which as we have seen previously only happens on.

It was originally intended to allow a single pushbutton switch on the dash of a vintage car to provide a latched function. Constant to momentary output positive input positive output relay wiring diagram. There are single pole high amperage switches are suitable for shallow back panel applications. Choose from our selection of momentary relays including flange mount spade terminal relays thin spade terminal relays and more.

In other words it works as a mechanical latching relay but the circuit backs to the start condition when you switch off the power supply. Attach an end of the momentary switch to the wire connected to the input pin. The capacitor allows the coil of the relay to be energized until the capacitor stores a charge thus de energizing the coil. The relay only draws current when it is being switched.

This thread is archived. Do this for both relays. There are also switches made of explosion proof stainless steel handling pressure from 100 to 1000 psi. Use these relays with circuits that control electric signals for plcs and microprocessors.