project question

[dksktm]

hey I am making a blinking ckt. and i wanted to know if there is any way if I can vary the capacitance in the ckt. just like a pot. for the resistance..

It would be really handy and interesting..
lemme know....
thankx

 

[Nigel Goodwin]

Use a variable resistor instead, far easier and cheaper - variable capacitors are available, but are EXPENSIVE and only in small values (pF).

 

[Hero999]

Please post a schematic.

 

[HarveyH42]

You could run several different value capacitors through a dip switch. This way you could choose a range, and fin tune with a pot. Also, caps in parallel add together, so you could get a lot of flexabiliy.

Variable capacitors aren't cheap, and usually in the picofarad range. You really won't see much change in flash rate using them for something like this.

 

[aljamri]

Harvey's idea with Resistors.

You could run several different value capacitors through a dip switch. This way you could choose a range, and fin tune with a pot. Also, caps in parallel add together, so you could get a lot of flexabiliy.

or as resistors are much easy to find, fix a large capacity capacitor and use Harvey's idea of DIP switches to choose the Resistance, and get the variation in cominations.

salam