Opto Isolator information, and help

[crashmasher]

I have a simple button radio remote, much like a car remote, that I am using to turn on a circuit. I want to be able to activate this remote using a 12v power supply. Through research I have heard that an opto isolator would do the trick by "hotwiring" the button points to the isolator so that when a 12v is applied, the button acts as if it were being pressed. I have not used these before and could use some help determining the correct opto isolator to use, and or a better way to go about this process.
Thanks in advance.

 

[mrinalmani]

Hi there...
Unfortunately your question is too jumbled up to understand. Make it clearer. Bikes, cars etc etc is a different story, do not mix everything together. Write down point by point what is your "circuit" supposed to do. May be then someone can help.

 

[betwixt]

Very unclear but I think what Crashmasher is trying to do is use the transistor side of an optocoupler as a power switch. That is entirely possible but most optocouplers are only good on DC and at low voltage and current so we need to know what exactly your 'circuit' demands by way of power. I think you are expecting more from an optocoupler than it can provide, for example, it cannot decode or even see a remote control unit, you still need support circuits to do that.

Brian.

 

[crashmasher]

Very unclear but I think what Crashmasher is trying to do is use the transistor side of an optocoupler as a power switch. That is entirely possible but most optocouplers are only good on DC and at low voltage and current so we need to know what exactly your 'circuit' demands by way of power. I think you are expecting more from an optocoupler than it can provide, for example, it cannot decode or even see a remote control unit, you still need support circuits to do that.

Brian.

I have a radio receiver and a key fob type remote. I want to activate it using a 12V which would be on a motorcycle. As in brake lights turn on, key fob transmits. If an opto isolator is not the correct thing for this job, what might work better in its place. I put alot of background info in the original post, but was told that I was being too informative.

 

[FvM]

The switch of the "button radio remote" is usually enabling the battery power supply, at least in case of a single channel remote. You should find out the involved current and voltage to design an external activation circuit.

Presumed that the remote is powered by a dedicated battery, you don't necessarily need an opto isolator, just a switch transistor. Alternatively, the battery can be replaced by a voltage regulator powered from external 12 V.

 

[ard]

With an opto-isolator, there are a few parameters you'd have to contend with to make it work. Instead, just use a relay, that would absolutely simulate the button being pressed. The n/o contacts across your remote button (polarity doesnt matter) and the coil of the relay connected to your trigger (source). Just make sure the relay coil is rated for the voltage you intend to use as the trigger.

Regards,

Anand.