Linear VCO with Ramp and Squarewave outputs

358

05:42:49

The voltage controlled current source charges the capacitor at a rate that is directly proportional to the charging current and hence directly to the input voltage. When the capacitor charges to the upper threshold, in this case 8 V ( 2/3 of 12 V ) at which point the discharge transistor in the 555 discharges the capacitor and the cycle repeats. The brief -ve  going pulse at the output of the 555 is connected to a counter in order to provide a square wave ( at half the frequency of the oscillator ) the ramp waveform is buffered by the opamp to prevent the load interfering with the charging of the capacitor.

published 7 years ago

hurz

7 years ago

In reality the frequency is double as high then here in EC simulation, check this as explanatiin http://everycircuit.com/circuit/6753892830806016

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