Hello!

I fear that the specification of the problem is insufficient.

What are the voltages, currents, "dynamic"?

Level of control signals?

Even today can often be a reasonable and simple solution suitable relay - switched via suitable transistor.

Hello Sir, thanks for the reply. 

The programmable DC source that I have has Dual Range, Single Output: 0-15V/0-3A) or (0-9V/0-5A); Output power: 45 Watts. I will be using the 0-3A range most often (it provides higher precision).

Additionally, 1 switch per second (for a couple of minutes) is more than sufficient for my application.

Please help. Regards.

Hello Prashant,

You can use BJT power transistors/MOSFETs to switch the loads upto 3-4Amps and 24VDC with simple logic (5VTTL/3V systems) signals. You can try first with 12V,35W automotive lamps so that you are sure of the current getting switched at the level and then replace the lamps with your "ACTUAL TARGET LOADS". By this way you can learns if there is any switching discontinuty or noise and also the switching  or changeover time required by your experiment.

I hope that this solution would work for you.

Best Luck!

Hello Prashant,

If you use a FET (which is probably better than BJT - the problem of its saturation voltage), you must pay attention to the channel resistance in the ON state. Voltage drop times the maximum current should not "exceed the the precision of your source."

Thank you Profs. Waichal and Josef. I will look into the possibility of using BJT and FET. Since I am NOT from electronics background, I would be looking for some standard circuit diagrams in which actually these BJT/MOSFET/FET are being used for the switching applications. Please froward me any literature that you can recollect, and/or any low-cost commercial which actually uses these principles for switching.

Regards.

I advise you to apply data from data vendors. They are often very detailed and verified. /datasheets, application notes/. Enter on google the password "resistance channel in the on-state" (or something equally intelligent:-), and the ride can begin.

Hello Prashant,

You can send me your exact requirement and then may be I can help you.

Best Luck!