12v latching relay solid state switch - momentary 12v pulse toggles on/off

12v latching relay solid state switch - momentary 12v pulse toggles on/off

FAQ: Do you have a 12v latching relay?

Please Note: This page is here for legacy purposes only. The impulse latching switch has been replaced by our new educational ESP32 Micropython kit, with a programmable low voltage relay module that has almost unlimited capabilities.

Yes, we have an SSR (solid state relay) 'smart switch' with latching and optional timer capabilities! If you have ever had trouble finding a latching relay that is toggled on/off by a momentary 12v pulse, here is a great solution. The programmable nature of this switch means it can be used in many different ways.

Double pole latching relays require 2 switches to operate, and regular single pole latching relays require polarity reversal to operate. But what if you want to use a momentary contact 12 volt switch to toggle a circuit on and off? Our DCC-2-SW solid state mosfet switch provides a perfect solution.

It draws a miniscule standby quiescent current of 0.03 mA @ 12v (great for solar powered circuits), and a very low 0.5 mA @ 12v when operating under load. It has an output handling capability of 7 amps @ 12v and can be quickly configured simply by adjusting 4 switches on the side of the unit. Here are the settings:

1Timer Control1 to 100 sec0 to 1 secprogrammable latching impulse relay switch settings
2Output Contactsnormally closednormally open
3Output Modetimedlatched
4Trigger Polaritynegative (-)positive (+)
yellow color indicates default settings

In latching mode, it will trigger with either a momentary pulse or continuous input, whenever a signal is sensed. When that trigger input is applied while it is on (in latching mode), it will turn off. It does not have to be a 12v trigger signal - it could be (for example) a 5 volt TTL input from a microcontroller unit (MCU).

The output can be configured as normally on or normally off, and the input can be configured to receive either a positive or negative triggering pulse. It will activate on the leading edge of a negative pulse, or the trailing edge of a positive pulse.

There are two timer ranges, from zero to 1 second, or from 1 to 100 seconds. The timed output can be precisely set in either range simply by rotating a small control, accessible at the side of the unit.

The unit ships with 2 wiring harnesses, one for output (heavy gauge wire, fused at 7 amp) and one for input control (lighter gauge wire, fused at 3 amp). Here is the wiring information:

Harness 1 (INPUT: 3 pin connector):

  • Red: +12v power re operation of internal circuitry (3 amp fuse)
  • Black: 12v ground
  • Green: trigger input, provides input pulse to control operation of latched or timed output. You could connect this line to one side of a spring loaded push button switch and the other side of the switch to + or - battery source. Pushing the button once would trigger the output on, pushing it again would turn it off. You could wire more of these switches in parallel to create multiple operating locations

Harness 2 (OUTPUT: 2 pin connector):

  • Brown: connect to +12v or -12v power re operation of output circuit, depending on polarity desired on yellow output wire
  • Yellow: power output line (7.5 amp fuse). Connect your load between this wire and ground
  • Yellow output polarity can be reversed by connecting brown wire to negative or positive source

buy programmable impulse latching relay in our online store

We sincerely hope you enjoy using these advanced switches; if you have any questions, please feel free to contact us at any time!