Latching relays are electromechanical devices with mechanical contacts. It has 2 coils, one to latch the contacts closed, the other coil is to latch the contacts open. Only one coil at a time can be driven with a short pulse of current from 10 mS to 100 mS duration. The coil current is not meant to be continuous. The contacts can be SPST or SPDT or DPDT or have many poles for special needs.
Questions tagged [latching-relay]
82 questions
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Should I protect against collapsing field effects of a microcontroller-driven small-signal relay coil?
I am building a simple engage/bypass switch for musical (e.g. electric guitar) effects. The signal switching will be done by a single coil (bistable) latching relay, such as the Panasonic TQ2-L-5V. The user interface is a momentary SPST…
Matt
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Are the coils on a 2 coil bistable relay interchangeable?
Are the set/reset coils on a 2 coil magnetic relay actually any different if the contacts are form C? The datasheet lists one as "operate" and the other as "reset", but in practice they both just switch the contact from one pin to the other,…
Teo
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4
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Relay coil suppression
I am following this application note for relay coil suppression. It suggests a diode and zener in series to be used for better contact life. I am using Panasonic ADW1212HLW relay. It's a 2 coil latching relay with a coil voltage of 12 V. Coil…
Whiskeyjack
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Is a self-locking relay the same thing as a latching relay?
This self-locking/inching WiFi relay can be configured to work in self-lock mode, in either NO or NC mode.
I’m not sure if self-locking means the same thing as latching. Wikipedia says:
A latching relay maintains either contact position…
WhiskerBiscuit
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2 answers
Driver circuit for dual-coil relay
I have a dual-coil relay. The coils are rated at 12 V. The coils set (or reset) at 6 V, and require a pulse of between 15 and 100 milliseconds.
The relay is TE Connectivity, part # V23130-C2021-A412.
I am trying to make a driver that will pulse the…
andy_r
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How do I wire a transistor to a dpdt relay
I have TQ2-L2-3v DPDT relay that is getting activated by an ESP8266-12e pin. The problem is the pin doesn’t always output enough current to activate the relay so I want to wire a transistor (2n2222) to it. My question is since the only relays I have…
user1114881
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4 answers
Normally Closed Latch Relay
Are there any relays that essentially have the same logic as an SR Latch? Specifically I need one that will latch when power is lost to the coil and then require a separate signal to reset or "unlatch" the signal. I have found many normally closed…
mayna
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How to select a Relay that can handle a load of 42V, 3A DC?
I want a relay that can be controlled by a Raspberry Pi and can handle a load up to 42V and 3A DC. I was looking at this: relay which is rated at DC 30V/10A. Although, 30V is less than 42V but I was wondering if this could still work as I found a…
Ahmed
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2
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3 answers
Relay to switch lights on from gate motor
I'm installing a 24V sliding gate motor (Powertech 500) and was hoping to power two 12V LED wall lights of it as the gate opens.
Unfortunately the motor doesn't have an input connection for lights but does for a flashing light. This connection gives…
Op.Ivy
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Power ESP8266-12e for 0.5 seconds after power cut
I have an ESP8266-12e (ESP1) that is connected to Blynk with a momentary button. When the button is activated it makes pin D5 HIGH which goes through a transistor and powers the set side of a latching relay. When this happens the relay turns the…
user1114881
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What causes voltage to increase from 12V to 36V as specified?
Reference article and paragraph:
Relays, Selection & Usage (Part 1) - 8 - Latching Relays
Below are two simplified circuits of dual-coil (A) and single coil (B) latching relay drivers. As is readily apparent, the dual coil version is far simpler,…
skmagiik
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Review of dual coil latching relay driver with single input
I need to drive dual coil latching relays from a single input signal. Following are my assumptions:
low-side drive of the coil
coils connected to 12V automotive
coil resistance unknown, assumed 1A will be more than sufficient
input floating -> 12V…
ARF
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2 coil latching relay initialization at power up
I have this simple circuit
My concern is that it has of course a kind of memory as the relay is mechanical.
I would like OUT1 selected at power-on, whatever the state before the previous power off.
Will this do the job?
Jibeji
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Are there relay designs that draw currents from its switching source?
Most of the time a relay is powered from a low-voltage DC source like a battery or a permanent stable DC power source. However are there modern relay designs that draw current from the circuit that they are actually switching? Perhaps a smart relay…
Nederealm
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Automatic voltage selection using SPDT relay
I'm working on a design with two voltage inputs and I need to give priority to one of the two inputs when both are plugged simultaneously. Both must also work individually.
the first input (V1) is from a battery (12VDC)
the second input (V2) is…
TunableWhite
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