| Author |
Message |
faraz101
Joined: 07 Mar 2007
Posts: 97
Helped: 2
|
 15 Oct 2007 17:08 555 timer pwm |
|
|
|
|
i have build 555 timer pwm circuit and i am varying the motor speed with the variblre resistor b/w pin 7 and 6.but i want to control the speed form external analog voltages which ranges form 0.80v to 1.20v.
any ideas
thanx
|
|
| Back to top |
|
 |
A.Anand Srinivasan
Joined: 15 Oct 2005
Posts: 1792
Helped: 216
Location: India
|
15 Oct 2007 17:33 pwm 555 |
|
|
|
|
| the control pin5 can be used but a amplified version of the 0.8 to 1.2V signal would be needed as far as i know....
|
|
| Back to top |
|
|
faraz101
Joined: 07 Mar 2007
Posts: 97
Helped: 2
|
16 Oct 2007 3:32 555 timer pwm circuit |
|
|
|
|
i already work on it but it is not giving a wide speed range.coz pin5 already have some voltage about 3v.
thanx 4 reply
|
|
| Back to top |
|
|
Google
AdSense
|
16 Oct 2007 3:32 Ads |
|
|
|
|
|
|
| Back to top |
|
|
ultrabrains
Joined: 14 Feb 2007
Posts: 115
Helped: 8
|
15 Nov 2007 6:15 555 pwm |
|
|
|
|
you can connect a resistor to ground to reduce the voltage on pin5 .
i worked on it a long time ago and i used a transistor circuit to pull th evoltage at pin5 to ground and it did work well
cheers
|
|
| Back to top |
|
|
A.Anand Srinivasan
Joined: 15 Oct 2005
Posts: 1792
Helped: 216
Location: India
|
15 Nov 2007 13:43 555 pwm circuit |
|
|
|
|
| pin5 will have a voltage because it is part of a internal voltage divider.... it can be varied externally according to our need....
|
|
| Back to top |
|
|
yogi
Joined: 08 Jan 2005
Posts: 345
Helped: 17
|
02 Dec 2007 12:39 pwm with 555 |
|
|
|
|
if you are using potentiomenter, then you require just one potentiometer and a diode with 555 astable multivibrator circuit
http://www.geocities.com/njbibin/robo14.html
Bibin John
www.bibinjohn.tk
|
|
| Back to top |
|
|
