wiring diagram for switching a 12v light using a latching relay and a 4.5v pulse from a receiver of a remote signal

Thread Starter

ajbw

Joined Feb 28, 2022
4
I want to switch a 12v light using a latching relay, a 12v battery and a 4.5v pulse - 3 seconds long - from a receiver of a remote push button signal.
The relay is a Panasonic TX2-L2-12v.
Can anyone help me with a wiring diagram?
Thanks.
 

AnalogKid

Joined Aug 1, 2013
10,067
The question is not clear. Given a 3 second long command pulse from the receiver, how should the circuit operate:

1. The relay closes on the leading edge of the command pulse, and opens on the trailing edge 3 seconds later? This is momentary operation: the system operates as if a momentary pushbutton were wired to a standard non-latching relay.

2. The relay closes on the leading edge of the first command pulse, and opens on the leading edge of the next command pulse? This is alternate-action operation; press once for the relay to actuate, press a second time for the relay to release.

1)... 2)... Other - ?

Also, is the relay part number in post #1 correct?

ak
 
Last edited:

crutschow

Joined Mar 14, 2008
29,844
To eliminate the large current through the diode of the non-operating coil which must be provided by the 555, it might be better to put the coils in inverse series, requiring only 1 capacitor, such as below:

1646148851679.png
 

AnalogKid

Joined Aug 1, 2013
10,067
Assuming the TS wants the circuit to operate in a momentary mode . . .

If the relay coil current pulse time is set by the coil resistance and C3, what is the function of C1? Isn't the 555 functioning as a simple half-bridge driver? If so, the circuit is operating at the edge of the relay's specified operate time. But wait, there's more.

The rated time is based on 12 V operation, but the 555 headroom and diode Vf combine to reduce the coil peak voltage to less than 10 V. I would increase C3 to at least 22 uF. 47 uF would be better.

ak
 

sghioto

Joined Dec 31, 2017
3,296
what is the function of C1?
C1 is the set-reset component, charges to 12 volts when the pulse goes to zero. Second pulse resets 555 by applying the 12 volts to pin 2-6 combo.
C3 value dependent on relay characteristics, 47uf probably more realistic.
 
Last edited:

Thread Starter

ajbw

Joined Feb 28, 2022
4
The question is not clear. Given a 3 second long command pulse from the receiver, how should the circuit operate:

1. The relay closes on the leading edge of the command pulse, and opens on the trailing edge 3 seconds later? This is momentary operation: the system operates as if a momentary pushbutton were wired to a standard non-latching relay.

2. The relay closes on the leading edge of the first command pulse, and opens on the leading edge of the next command pulse? This is alternate-action operation; press once for the relay to actuate, press a second time for the relay to release.

1)... 2)... Other - ?

Also, is the relay part number in post #1 correct?

ak
The relay part number is correct.
2. is correct - press to switch light on - press again to switch light off - should not require a complicated circuit.
The question is about how to connect the TX2 relay to the receiver, the 12v battery and the light.
Thanks for your interest in this.
 

eetech00

Joined Jun 8, 2013
3,163
I want to switch a 12v light using a latching relay, a 12v battery and a 4.5v pulse - 3 seconds long - from a receiver of a remote push button signal.
The relay is a Panasonic TX2-L2-12v.
Can anyone help me with a wiring diagram?
Thanks.
What is the receiver part number? So we can look it up and determine interface requirements.
 
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