Newbie - momentary relay

Thread Starter

Ruffracer

Joined Aug 1, 2020
6
Hello all you geniuses out there! My knowledge is minimal when it comes to electronics. I have wired a few relays here and there mostly car audio stuff. But I am trying to build a relay and am having no luck. I have searched and tried a few diagrams found on this forum, none of which have worked. I have no idea what the circuit would even be called to search for it. I will explain what I want it to do and hopefully someone can explain to me (needs to be very dumbed down) how to create / buy it.

So I have an inverter I want to install in my vehicle. It has a momentary push on push off button on the front to turn it on or off with one press. You kind of have to hold it down for a second or two for it to turn on, but to turn it off you just press it once. It also has the CAT phone wire to turn it on remotely.

I want it to turn on with the 12v accessory wire and turn off with a delay of like 60 seconds. Is this possible? I have tried the attached diagram on the remote switch (soldering to pins in switch) and I can get it to just turn the power light on and off. It doesn’t actually trigger the switch. I know now it cannot be done this way but I then put a delay off relay on the 12v accessory wire for the delay and it doesn’t even light up anymore.
Any help would be greatly appreciated!
 

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dl324

Joined Mar 30, 2015
11,264
Welcome to AAC!

You could use a 555 timer. Have the accessory 12V drive an inverter that triggers a one shot. You'll have to AC couple the trigger so the one shot can time out.

From a Signetics Analog Handbook:
clipimage.jpg

Depending on the current requirement for the relay, the timer may be able to drive it (200mA max).
 

MisterBill2

Joined Jan 23, 2018
6,727
Are you telling us that the inverter has completely stopped eotking, or just that some control scheme is not working.??
Is the phone wire connection arrangement the same as the single button control scheme?Or is the remote a 2-button plus indicator setup? I have seen both.
It may be that disconnecting the power did some actual physical damage, or maybe just confused the logic inside the device. If the inverter failed because of being disconnected then I would sent it back and get a different brand for a replacement. Using a capacitor/relay combination for the short turn-on pulse should work, generating a much longer pulse from the opposite contact when the ACC is switched off should also work. One pulse relay with the 87A contact feeding the short pulse capacitor and the 87 contact feeding the long pulse capacitor should work. Presuming 87A is energized from 30 when the relay operates and 87 is powered when the relay is not energized.
 

sghioto

Joined Dec 31, 2017
1,329
Ruffracer if you are trying to do this using only relays the task is impossible. Just to clarify you need a contact to close for 2 seconds that is activated by the 12 volt accessory through the ignition switch to turn on the inverter. When the ignition switch is turned off you want a delay of 60 seconds before another contact closure of 1 second to turn off the inverter. Is that about correct?
Steve G
 

Thread Starter

Ruffracer

Joined Aug 1, 2020
6
No the inverter works fine, when I manually press the button.
I will have to do some research regarding the 555 as I am not familiar. Does it just interrupt the positive wire?
 

MisterBill2

Joined Jan 23, 2018
6,727
I realize now that the suggestion that I provided does not include the minute delay after ignition shutoff. For that part you would need to pick up the delayed lights shutoff controlled line. And not every car does that the same. But in mine the accessory keeps the radio playing for another minute after ignition switch off, so the delayed accessory control line could work.

But what is so bad about manual switching on the inverter? What does it power, anyway??
 

Thread Starter

Ruffracer

Joined Aug 1, 2020
6
It’s for a computer. That’s the reason for the delay off, need to give it time to shut down before killing the power.
Just want to thank everyone for there suggestions and help with this.
 

dl324

Joined Mar 30, 2015
11,264
Will the above board do the momentary “press” for the on off button?
Do you mean you want to use a switch in addition to the accessory switch?

If you want to be certain before buying, you should contact the Amazon seller and ask. Maybe they'll give you the instructions before purchasing.
 

MisterBill2

Joined Jan 23, 2018
6,727
OK, for a computer in a car, if it is a laptop or tablet, why not a direct DC to DC supply that will not draw much power beyond standby when the computer shuts down? And some portable computers use a 12 volt battery pack, which in that case a direct replacement connection would get past the need for anything external besides a filter and a fuse.
 
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