1Khz Square-Wave Generator


Posted on Feb 27, 2013

When the output is high, R3 and R4 are in parallel, and CI charges via Rl until the current in R2 equals that a


1Khz Square-Wave Generator
Click here to download the full size of the above Circuit.

t the noninverting terminal. This action occurs when CI"s voltage rises to 2/3 of the supply voltage. At that point, the circuit switches regerier-atively. The output switches low and CI starts to discharge via Rl. Now, R4 is effectively disabled and the current to the noninverting terminal is determined solely by R3, so CI discharges until the current through R2 falls slightly below that of R3. This happens when the voltage across CI falls to about 1/3 of the supply voltage. At that point, the circuit again switches regeneratively, and the output again goes high. This circuit is useful for generating symmetrical square waves with maximum frequencies of only a few kHz. Because of the poor slew-rate characteristics of the LM3900 (0.5 V7/is), the output waveforms have rather slow rise and fall times.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Mains Voltage Checker
wireless FM bug
Motor direction controller
lm35 for precision centigrade
Bluetoothß„? Front-end Ic T7024 Design Guide
SimpleTimer with Musical Alarm
One-IC two-tones Siren
High Frequency VCO Design



Top