# 60hz Astable 555 timer circuit not oscillating

Yet another electronics newbie here :) I have tried to construct a simple 60Hz oscillator using a NE555 timer in astable mode, yet it does not seem to be oscillating. To test it, it has been connected to a speaker as I do not have access to an oscilloscope or any other fancy test equipment.

R1 and R2 are 10 and 47 ohms, and C is 220uF. According to my own calculations and to online calculators this should give a frequency of ~63Hz. I have tried the circuit using other resistor values - all of which work - but do not give the desired 60Hz. simulate this circuit – Schematic created using CircuitLab

## 1 Answer

the top end of R1 should connect to 5V, replace c3 with a wire.

all the resistors should be 10 times higher. those values are pushing the limits, make the capacitor C1 10 times smaller to compensate for the increased resistors.

• Ah crap. Made a mistake when making the diagram. R1 is actually connected to 5v. How would I go about fixing the problem then? I only have access to 220uF, 100uF and 470uF caps. But I suppose I can order some more in, if there is no other way – Levi Jan 8 '16 at 5:26
• c1=100uF and replace R1= 68 ohms might work, – Jasen Jan 8 '16 at 5:28
• I'd normally use much smaller capacitors like 100nF and resistors around 100K – Jasen Jan 8 '16 at 5:29
• Wouldn't making c1=100uF and R1=68ohms cause f=~89hz? – Levi Jan 8 '16 at 5:33
• Regardless, I'm going to have to get some more parts. Thanks for the help! – Levi Jan 8 '16 at 5:35