User Manual

VMP502
V. 02 – 25/10/2019 25 ©Velleman nv
A 555 timer is a medium-sized IC device which combines analogue and digital functions. The 555 timer can
work under three modes. Here, the astable mode is used to generate square waves.
Under the astable mode, the frequency of the output waveform of the 555 timer is defined by R
1
, R
2
and:
In the above circuit, R
1
=R
2
=10 kΩ=Ω; =100 nF=F. Frequency:
After connecting the circuit, use an oscilloscope to observe the frequency of the output waveform. It is
consistent with the above calculated result.