- Joined
- Nov 17, 2011
- Messages
- 13,337
I just found this easy method described in EDN to create a 50:50 waveform from a 555. No need for diodes as usually shown.
Maybe put EDN on a whitelist? Lots of ads, agreed, but also lots of useful information.EDN doesn't like my ad-blocker
It does. Thanks.I hope it works.
Yes, I have previously used that technique (simulation below):
It uses a third resistor in series with the discharge transistor to equalize the charge and discharge times of the timing capacitor.
View attachment 54658
My simulation is realistic in that it shows what the circuit does with the 13.7kΩ resistor I used.Your simulation would be more realistic
Do you mean R2 or R3?What output waveform does your simulation predict if R2 = 0, all other values left unchanged?
Below is the simulation with R2 removed:"Do you mean R2 or R3?"
R2. The resistor that connects to C2, THRS, and TRIG. Make it zero ohms and see if what your simulation then predicts for the "high" and "low" times look realistic.
Whose fun?Just for fun, you might want to try R3 = 22k, no other change.
Here's the simulation.it should (if your simulation works accurately) make (pretty close) to a 50% duty cycle. Wouldn't that be fun?
The data sheet says “typical”, not set in stone. Nothing is perfect. You should know that.Trigger voltage is 1/3V+, therefore 1.667V when V+ = 5V, not ~1.85V as shown by your "accurate" simulation?