Looking for a board from Rod's PWM design
w9jsw:
Does anyone have a board of this? If not, I will make some.
John
w9jsw:
I already have a board from Nigel's design. Made them quite a while ago. Which one is preferred? I like this one due to lower parts count. LPF seems more straightforward.
John
w9jsw:
Got tired of waiting... ;D
Actually, i really like making boards.
vk3alk:
Hi John..
Your board looks great ...
Would suggest squeezing a .1uF capacitor where C10 is .... maybe moving that 10uF back up the line...
Also would change C9 to a 100uF low ESR type...
There is so much squarewave switching going on at that point an ordinary electrolytic might not last the distance over time...
That area is really crowded and the 100uF capacitor is larger in size then a 10uF one....
Wayne
w9jsw:
Thanks Wayne!
I recall some discussions on diodes in the charge pump area. Are the 1N914s adequate here?
Made the changes you suggested. Also added another 0.1uF at the other end of the 15V rail by U1.
This a good selection for low ESR? 100V rating enough?
Is there any special requirements for C11? I thought so, so provided a large footprint for a 2220 Mica one. Ceramic would be much cheaper.
https://www.mouser.com/ProductDetail/Panasonic/EEU-FR2A101B?qs=u16ybLDytRZBZOsu6DbX5Q%3D%3D
John