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).
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Soft latching power circuit stops working after heating
I implemented the below latching power circuit (can be found here https://circuitcellar.com/resources/quickbits/soft-latching-power-circuits/) that has 1 button to turn the circuit on and is turned ...
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Latching comparator always starts at latching position
I build a over-current protection circuit using a latching comparator, below circuit diagram is the simplified version (without the current limit circuitry):
simulate this circuit – Schematic ...
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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 ...
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How to make latching valve turn to close orientation when power fail when controlling it with H bridge of MOSFETs?
I am making a circuit which controls a latching valve this valve is going to be controlled with 2 pins from my MCU. The valve must turn to the close orientation when power fails either from battery or ...
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Emergency stop behavior - state of normally open switch when activated
I am using and emergency stop in an application. It is a push button with a twist release. I have the main circuit connected to the normally closed side and a detection circuit wired to the normally ...
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Power latching circuit issue
I'm working on designing a circuit to latch power to an ATTINY85 when a button is pressed, then turn the power off when the button is held, but for some reason, the below schematic is not working. ...
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LDO self-latching circuit review
I am putting together a latching circuit and just want to make sure I am not missing something obvious that would prevent this from working. Circuit:
Note: the actual LDO in the design is XC6701B502PR ...
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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 ...
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Does this latch have a name?
I'm looking for a circuit like:
Where, on the rising edge of any input, the corresponding output latches on and the rest of the outputs turn off. Sort of a mutually exclusive selection latch.
Does ...
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Transistor Latching Momentary Switch Help
Attached is a circuit for two "latching" transistor circuits using a momentary switch to toggle a relay. Switch 1/ Relay 1 works perfectly; toggles on/off as it should.
Switch 2/ Relay 2 ...
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Is this circuit correct and safe to bypass my latch circuit, turning on the load every time I connect it to 5V?
I have this working on/off latch circuit below that works on a 8.4V battery.
I can charge and bypass the battery when I connect the circuit to a 5V charger, while still providing supply to the load ...
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Transistors falsely latch with EMI
I have a very basic NPN - PNP latching circuit:
[Sorry for the upside down image]
The latch initially is off, and when the op_amp_Signal_and_latch turns on, the ...
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Latching interval timer with positive trigger
Can I create a latching interval timer circuit with a 555 chip using a positive trigger (which is not pulsed but remains high during the timing interval and afterwards) without retriggering the timer? ...
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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, ...
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Bluetooth IC performance improves after resoldering/heating
This is a very general question and I'm trying to brainstorm and get some insight into potential issues, things to watch out for etc. Unfortunately, I can't share the schematic or the datasheet.
My ...
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Fan speed control using relays
I would like to control the speed of ac 240 vac fan using capacitors as shown in the diagram below. Since the project is an ESP32 based fan speed controller, the rotary switch in the schematic will be ...
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Unstable latching circuit
I'm trying to implement a latching circuit for around 4.1V of voltage (LiPo battery).
Below is the circuit:
The problem is that the circuit is always on as soon as the power is applied (so even ...
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Replace transistor-latch with thyristor: is my circuit correct?
Please consider the following two circuits:
On the left, is a transistor-latch using a PNP and an NPN transistor.
I'd like to replace those two transistors with a thyristor, mainly to get a little ...
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How can I quickly discharge a capacitor in a Zener on-delay timer circuit?
I have a project that requires using a delayed latching circuit. I found two circuits that I could combine, a on-delay timer circuit from TheEngineeringMindset and a latching circuit from ...
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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 ...
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Using a level triggered latch as a negative edge trigger for negative logic
I am a (relatively) new hobbyist and I am working on a project that uses an old video chip (v9938.) The chip is designed to use old DRAM, with a multiplexed 8 bit address bus, and *RAS and *CAS ...
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N-MOSFET and NPN latching switch
I've seen many latching circuits through searching and reading some simple circuits.
Most use NPN+PNP combination, some bistable ones use two NPNs, some use DPDT relays.
Is the following circuit going ...
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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 ...
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Latching relay but self resetting (to off) on power off?
I'll try explain my problem:
I am trying to make a simple circuit that powers on when a momentary switch is pressed but then stays on until the power source (feeding the lamp) is then removed.
I want ...
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ADW1205HLW latching relay heating issue
I want to take the advantage of latching relay to remove power dissipation from the circuit.
I am also using ADW1205HLW dual latching coil relay but faces an issue of heating even after set or reset ...
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Need help on latching circuit turning on without pressing on/off button when battery is inserted
I have this latching circuit to turn on and off an MCU (ATTINY 167) and a led Driver, by using a 8.4V Lipo battery.
It works fine: pressing the button turns it on and pressing again turns it off. Also,...
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Need help to bypass the momentary switch in this latching ciircuit (but keep using it.)
I’m using this circuit to turn on and off an Attiny167 and an LED driver with the push of a micro switch.
My circuit is powered by an 8.4V battery.
In the “load” part of the circuit there’s a voltage ...
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Get the system to turn on using a voltage source
I am working on a project where i have a momentary push button and i am using this latching circuit to toggle between the two stats, the circuit is working fine.
I need to add a circuit to this one in ...
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How to cheaply build a latching relay system to disable a circuit until power is cycled?
This is my first post here. I have an aftermarket backup sensor that needs to be disabled when I back a trailer. I want to be able to push a button to disable it, but have it be automatically re-...
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Latching Push Button High Side Power Switch
I'm a beginner trying to design a long-push to turn off and short push to turn on push button switch. I've managed to find this design but when put into use in a 3.3V system, it does not seem to work. ...
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Need help in Latching ON/OFF switch
I am working on a latching on/off switch, There are many ways to do it by using discrete components. But I want to use an IC to perform that task. I found MAX16054 IC which is similar to my ...
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Momentary switch 12 V motor reverses game
I am trying to figure out how to control a DC motor with a momentary switch as a trigger and limit switches for stops. The trigger needs to be momentary because I need three of them in parallel at ...
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7408 quad-AND with diode latching: sporadic (and undesired) self-latching at power up
As an introduction to electronics, I am still working my way through Charles Platt's Make: Electronics (2nd edition).
This issue is about Experiment 21: A Powerful Combination
In circuit on ...
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Are there a way to join 2 I/O control lines using staircase two ways switches approach?
I am a newbie and would like to have a question and would like to have your advice.
Requirements: Control 1 relay (max current is 20mA) over 1 Arduino pin (pinMode as OUTPUT and state of this pin is ...
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Controlling AC relay with a single push button?
Is it possible to set an AC relay (220vac coil) ON / OFF by using a single push button (non latching) and some extra components but without the need of an additional DC supply?
It doesn't have to ...
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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 ...
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How to add a MCU signal to turn off this push button mosfet-based latching circuit?
I’m using this circuit to turn on and off an Attiny85 and a led driver with the push of a micro switch.
My circuit is powered by 7.4V battery.
In the “load” part of the circuit there’s a voltage ...
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Can't find suitable Bistable/Latching 12V DPDT Relay
I have a 12V actuator that is controlled by a 12V programmable timer. So my pulse is either power or no power. I am using a regular 12V DPDT relay which works fine.
However, I would like to use a ...
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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 ...
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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 ...
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Want to replace push-button with IR receiver
In the diagram below I want to replace that push-button switch Sw1 with IR receiver, I tried a lot with different combination with IR receiver and tried with transistor but I failed, so, please how ...
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Toggling 9A with ATtiny85 single-button-latch
I'm trying to use a nice one-button On|Off latching setup on ATtiny85. See for details the last one of these four: http://www.technoblogy.com/show?VOO
In a low-power set-up on my breadboard this is ...
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3V Soft latching switch
I apologize if this has been asked before but the answers I found are all over the top for this simple latching application.
I'm looking for a very compact solution:
1) 4.5 volt dc, 3 stacked hearing-...
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Persistent Mechanical Feedback
I am looking for a device (preferably in a small form factor) that can provide feedback for the user even after the power has been removed from the PCB (No, I don't want a battery powered solution.). (...
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Need a modified S-R latch
I have a comparator output who is normally high and goes low from time to time.
I need a latch which will change its output from high to low when the comparator's output change to low (and keep it ...
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Latching power button with force-off
There's been a lot of soft-latched power switch circuits discussed here and elsewhere on the internet. However, I can't wrap my head around how to implement the following requirements:
Battery ...
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Dual Coil Latching Relay with LEDs - Opposite LED Triggers on Trailing Edge
This is my first time using dual-coil latching relays (Kemet EC2-5TNU), and I'm running into some strangeness when breadboarding out the below circuit:
The coils switch without issue when sending a ...
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Latching Switch Pinout
I'm planning on incorporating a latching switch into my design:
https://lcsc.com/product-detail/Electrical-Switches_XKB-Enterprise-XKB8080-Z_C318860.html I also found the corresponding datasheet: ...
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Latching relays connected in parallel not working as expected
I have a project I'm working on where I need 4 relays to open when power is applied to the board and close when power is lost. I need to use latching relays to conserve power as the device could be ...
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How soft latch power switch in this specific circuit is possible?
I am trying to understand the soft power switch operation of a LED lamp I dissembled. The circuit of the lamp is depicted below.
The switch S1 can be considered as a momentary on switch (SPST). The ...
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