Fake car alarm

>>1044899
I'd probably rig it off something like the stereo ignition wire so when you do put the key in and the stereo turns on it closes the circuit to the LED
Obviously it would have to be battery powered

>>1044899

you will need a 2 pole relay. one with contacts normally open and normally closed.

the purpose of this is when the relay is off the contacts are closed in one position, when the relay is engaged the contacts close in the opposite position

to power the relay hook it to an accessory power lead so when you turn the key on it has power (like your radio does) and then it can deactivate the led. then when you turn the key off, it will open those contacts and close the other which you can wire to a direct lead to the battery to power the led when the key is off

id draw up a sinple diagram for this but I am not your personal research anon.

>>1044908

OP wants the LED to be OFF when the key is on.. and flashing when the key is OFF. I already told OP what he needs to do this

>>1044910
No relay needed.

Posative to permanent power

Negative to acc via 470 ohm resistor

>>1044912
I'm sure you could have inferred the same thing from that first post

>>1044899
Hey guess what if your car is so old that it doesn't have an alarm and immobilizer then nobody is going to want to steal it.
Even if they shipped it of to Africa nobody would want it
If you live in the kind of area full of joyriders then an alarm won't stop them either and are too stupid to understand immobilizers
Stop leaving bars of gold on the back seats and you will be fine.

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thanks for replys..

a simple relay with constant power sounds good..simple enough.

on the same subject, do you know of any simple circuit - learning electronics books that are good visual manuals I could get started with? The school text books I usually find are long-winded and lacking really good visuals..

>>1044951

Its just more degrees of security. nothing is 100%, but the harder I make it, the better it is.

Stereo, a nice coat (your favorite) and a few other knick-knacks these fucking methheads steal cost me time and money.

>>1044951
You are 100% incorrect. Old cars make up almost all car thefts. Car theft is becoming more rare by the year as older cars are taken out of service.

Jamal used to be able to boost your 88 Civic with a screwdriver. Now all he can do your 2016 Camry is put a brick through the window and steal your bag you left in the back seat.

>>1044973
This.

I knew someone who recently just had their 90-something Accord stolen, recovered, then attempted stolen AGAIN. People want them for parts and or because they are easier to steal.

OP, why does the light have to be off when the car is on? The relay method sounds nice, but always-on isn't bad since you wouldn't expect it to get stolen while you're in it. A simple on-off toggle would also be easy.

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>>1044966
>a simple relay

You don't even need one.

Pic related is all you need.

>>1045063

Sometimes long night drives. I turn the internal dimmer all the way down to no lights, makes it easier when its 1am and you have 2 hours to go. Any bright/flashing light in my constant field of vision gets to me.

>>1045131
Its a preference thing because I always have mine hard up and have only turned it down to watch it work then thought I can't see that and turned it up again. Flashing lights would annoy me for sure.

>>1044914
>No relay needed.
>>1045102
>You don't even need one.

This is the simplest, easiest, cheapest way to go.

When the ignition is ON no current flows through the LED because both are at 12V.
When the ignition is OFF the LED is powered from the constant 12V with the 'sometimes on' acting as a path to GND.

>>1045223
>Tha fuck is that easier
because you just plug the ends of two wires into the fuse socket with the fuse blades

You have to have the LED
You have to have the resistor
You have to have wires to connect it to the car
You DON'T have to buy, mount, and wire the relay and then the LED to the relay - just the LED wires to the fuses.

>>1045227
ayy, I did deleted that, but, you too quick ;)
>You prob right, was brainfartedly thinking it more complicated than it is.

>>1045102
Huh? That's not going to be a path to ground when the ignition is off. It will be an open path. No pwr. No gnd.

>>1045235
Any loads connected to that line will do that. If there are none just throw a resistor in. Have done this irl for a headlight warning beeper and it worked fine.

>>1045251
Also you add a diode also in the case of headlights because it will reverse polarity the beeper otherwise.

>>1045251
Gotcha. So the 470 ohm resistor is calculated to be enough to add the potential difference.