Hi!

I want to build a constant current source boost converter for leds. I use 34063 ic with external n fet switch. The current meassured by a 0.1 ohm resistor and this voltage amplified to 1.25 V. My question is that is this circuit safe? I mean that the output is limited or can go so high (e.g. open output) which can kill? Thanks for reply.

 

You have to look at the available power input and the available power output. Circuits with voltages under 50V DC are generally considered safe, but the details do matter. As a rule of thumb you should consider the power output to be 80% of the power input. Once your design is complete you can do a more detailed analysis of the efficiency.

For example:
Input power is 12V @ 1 Ampere = 12 Watts
Output power is 12 Watts * 80% = 9.6 Watts
Now 9.6 Watts can be 48V @ 0.2 amperes or 16V @ 0.6 Amperes or any other combination that yields 9.6 Watts

Does that clear things up?

 

Than you for reply.
So will it be safe? Does the output limited (e.g. 50 V max) or should i handle the high resistance load case?

 

Than you for reply.
So will it be safe? Does the output limited (e.g. 50 V max) or should i handle the high resistance load case?

You need to provide some information on the power source and the circuit.
How can we answer your question without a circuit to evaluate?

 

The power source is 12 V from a computer psu. here is the circuit diagram: