PWM Circuit Q. change 30 htz freq to 150 htz?

For the PWM motor control circuit at http://www.eleinmec.com/article.asp?28 -

The astable freq is about 30 htz - what would I have to change to make the freq 100-200 htz ?

Thanks for your article and any help for the above Q

Michael

Posted by Michael (mike@4uq.com) on 21/08/2008, at 00:48 GMT

PWM Circuit - Change of frequency

The fomulae for the astable and monostable 555 timer are shown on the relavent data sheet info. Are you using the right units for your calculations? - Ohms and Farads which involve multiplying the relative values by power of 10 - namely 10 to power 3 for kilo ohms and 10 to power -6 for microfarads.

Posted by Robert Neill (varient412@yahoo.co.uk) on 25/01/2010, at 19:53 GMT