I am making a circuit with a 555 timer and calculating the frequency. But have been told that capacitors are 20% inaccurate. So my 100Hz might be anywhere between 80Hz and 120Hz is there a way round this? is it possible to buy accurate capacitors?

 

Yes it is possible to get higher accuracy. You just have to use caps such as film or ceramic with tighter tolerances, less temperature drift, and measure each capacitor's capacitance and cherry pick the best of the lot.

 

Yes it is possible to get higher accuracy. You just have to use caps such as film or ceramic with tighter tolerances, less temperature drift, and measure each capacitor's capacitance and cherry pick the best of the lot.

Any clever way of measuring capacitance without a capacitance meter?
My guess is probably not , but I thought I'd ask anyway

 

Put it in a 555 timer circuit and measure the frequency (or other oscillator circuit).

 

The usual way is to use a variable resistor to adjust the timing. Cheap, available, effective.

 

Thank you all for all your great ideas.
I am new to electronics, but another way round this is there something like a digital screen that will display the frequencies from a variable circuit?

 

Build a frequency meter.
Also, many DMM have frequency function.