Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [latching]

A circuit or component that maintains its state after being activated (e.g. a latching relay which only requires power to change its state, then maintains its contact position even without power applied to the coil).

A circuit or component that maintains its state after being activated (e.g. a latching relay which only requires power to change its state, then maintains its contact position even without power applied to the coil).

75 questions
4
votes
3 answers

Simple soft power latching circuit for a microcontroller

I'm building a simple device with a microcontroller and I'd like to be able to turn it on and off using the "hold a pushbutton for 2 seconds" trick that is found on so many consumer devices nowadays (bluetooth headset, USB powerbank, smartphone..…
Foaly
  • 151
  • 1
  • 8
3
votes
3 answers

Is there any such thing as a tristable, quadristable, etc. multivibrator?

The title says it all. Is there a discrete circuit that can produce 4 different outputs based on a single tactile switch click? I'd like to do this with either a discrete design or a 74373 since these are all the parts I have on hand. I'm living in…
Aaron Butkovich
  • 353
  • 1
  • 7
3
votes
2 answers

What's wrong with this latching relay circuit?

I've been told that this relay circuit should latch. I built it and it does not. I want the LED light to stay on after the N.O dP switch is is closed and then released back to its N.O. state. Using 24 VAC power with a 24 VAC LED signal light. I'm…
Ted
  • 31
  • 1
3
votes
1 answer

Problem with SCR latching circuit

I put this circuit together to demonstrate latching properties of SCRs but I'm finding that the SCR doesn't behave as I expected it to from the datasheet values. Specifically, I found that in the circuit as shown it will light when the switch is…
RichardD
  • 45
  • 5
2
votes
1 answer

Help identifying 6-pin SMD components with 46 L code

I am looking for the SMD below. Code "46" and vertical "L". It is used in a latch circuit and could be a NAND gate or equivalent, something like a flip-flop circuit. Here is the link to a circuit using this IC. Any ideas?
user2053949
  • 21
  • 2
2
votes
3 answers

Push button latch circuit - switch issue

I have built a single push on/off latching circuit as per the diagram. It runs from 12 V. It works, but the issues I have is that first, it is already on when I connect power, it should start off, second, I have to flick the switch extremely fast…
Grant Lee
  • 65
  • 4
2
votes
0 answers

Do I properly use Toshiba H-bridge TB67H400ANG?

I am new in this forum, so I am sorry if I don't properly ask my "question". I am a beginner in the making of circuits and Arduino programming. (first time using an H-bridge, first time doing Arduino). I want to create a fake recoil in a toy gun…
silvergoldengun
  • 21
  • 2
2
votes
1 answer

How to make this T-flip-flop circuit

I am trying to make a T-flip-flop circuit with a relay, which would: toggle on a button press (12 V) [default state: off] allow control from an external micro-controller (optocouplers) allow switching between standalone button control and external…
Jakub Smetana
  • 21
  • 1
2
votes
1 answer

12 V relay switch wiring

I had some heated seats retrofitted to my car. I have wired them so that a 12 V ignition signal activates a relay and powers a bus bar which then powers the seats. The switches are round ON-OFF-ON switches. So if someone leaves the passenger switch…
Ben Pettman
  • 121
  • 1
2
votes
3 answers

Circuit to turn microcontroller on when reed switch state changes (to monitor door lock state)

I'd like to build a circuit that provides power to a microcontroller (ESP8266 in this instance) when a reed switch is changed from closed to open AND when changed from open to closed. This is to be used in a circuit that will monitor the state of a…
Thinqer77
  • 21
  • 2
2
votes
1 answer

Latching power with LDO enable pin

There are lots of examples of latching circuits that use a single momentary push-button to turn on/off a circuit by combining two or more transistors. Some examples are: Simple soft power latching circuit for a…
rea104
  • 21
  • 4
2
votes
2 answers

Electrically toggle-able switch?

I'm wondering if a switch exists that fits this functionality I imagine: The user would depress the switch, it would latch and stay depressed. Once the product completes its function, the control circuitry sends a signal to the switch which…
K. S.
  • 123
  • 4
2
votes
1 answer

Making an automotive "dizzy" switch using a latching relay

My engine builder wants me to be able to turn my car over without it starting to pre-oil the motor due to a remote oil filter. The car needs to be wired so that the coil will not have juice until I push a momentary switch which will activate the…
Bigbaldy33
  • 21
  • 1
2
votes
1 answer

Using two momentary switches to toggle LED

So, this circuit should (in theory, at least) turn the diode on when ON button is pressed, and turn it off when OFF button is pressed. It doesn't though. The diode is powered on at the moment where I connect the circuit to power, and it switches off…
Baglison
  • 23
  • 4
2
votes
1 answer

Can we apply a longer pulse to latching solenoid than its rating?

I've a 6-12V dc latching solenoid, which needs 60ms of pulse to set it to on/off. I'll be using a microcontroller to generate the pulse. I've following questions. What if the generated pulse is longer (say 10x of the specified 60 ms) Will it…
Ouroboros
  • 223
  • 1
  • 8
1
2 3 4 5