bigboss59400 wrote:Thanks for your (big) reply but I have checked the transistor and the transistor was inverted
bigboss59400 wrote:So now that's work great (with a li-ion cell) however I need to put some water on paper even if it's doesn't works I used a 20M ohm resistor should I change it by a 10 ? (I speak for R1)
bigboss59400 wrote:Sorry about waste your time but I think if someone have a problem it could check on your post and see what to do...
Changing R1 from 20M to 10M will change the frequency of the square wave when the pencil isn't touching the paper, but won't make the circuit see the graphite lines any better. Try using a soft artist's pencil (4B or more) and draw wide, dark lines.
bigboss59400 wrote:my pencil is a 2H so I must buy another pencil with a high H ?
firstname.lastname@example.org wrote:...Pins 1 & 4 should be VCC, pin 8 should be GND and ...
email@example.com wrote:Pin 7 should show a square wave between VCC and GND, and pin3 should show a square wave between VCC and VCC - .65v
jszsj wrote:Sorry for my Englishmstone@yawp.com wrote:...Pins 1 & 4 should be VCC, pin 8 should be GND and ...
Why pin 1 should be VCC and pin 8 should be GND? The 555's datasheet said that pin 1 goes to GND and pin 8 goes to VCCmstone@yawp.com wrote:Pin 7 should show a square wave between VCC and GND, and pin3 should show a square wave between VCC and VCC - .65v
I tested my circuit,and I don't see square wave,my pin 7 is VCC and pin 3 is VCC too, my scope is arduino with arduinoscope, I'm not sure if the frequency is too high to measure
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