Looking for timer with two inputs

[billbaty]

I have thought of an experiment I want to conduct. I will need to have a timer device which would accept two DC inputs & output (undetermined voltage, but low, 12 volt or less) and switch between them at a variable rate from about one second to about 60 times per second. So when one input circuit is off, the other would be automatically on. I wouldn't need the timer to be run from the input current but could be run from a separate 12-volt current or plugged in to 110 household current.

Is there such a timer already on the market?

All the best

 

[KJ6EAD]

You can build it easily with a 555 timer and either transistors or solid state relay output (1 form C). How much current does it need to handle? I'm not aware of an off-the-shelf product.

 

[billbaty]

You can build it easily with a 555 timer and either transistors or solid state relay output (1 form C). How much current does it need to handle? I'm not aware of an off-the-shelf product.

Hi, Probably not much current. 12 volts @ around 5 amps. But I would like it rated higher and not run at its maximum.

 

[KJ6EAD]

Can you afford to lose 0.4 - 0.6 V from each source?

 

[billbaty]

Can you afford to lose 0.4 - 0.6 V from each source?

Hi, Yes, I probably could afford to lose some voltage. Are you suggesting some sort of switch/timer that would consume about 1/2 volt?

 

[KJ6EAD]

No, the power to operate the circuit would be independent, but semiconductor junctions like those in a switching transistor or solid state relay have an inherent voltage drop across them.