New Jarduino build gets started

[daplatapus]

Hmmm, unplugged the PWM fan wire and the fans ramped up to where I think they should be. Anyone hazard a guess what might be wrong? Where I should start looking?

[ScubaSteve]

Originally Posted by daplatapus

Hmmm, unplugged the PWM fan wire and the fans ramped up to where I think they should be. Anyone hazard a guess what might be wrong? Where I should start looking?

I'd start by poking around with your multimeter. Check the PWM pin to see what the output is and make sure you haven't accidentally reversed the ground and PWM wires, then start checking each part of your fan circuit. If I remember that crazy-assed circuit correctly, there is a chance the transistors aren't saturated and thus aren't acting like switches as they were intended to.

Also, check the programming to see what the minimum and maximum PWM outputs are. Most fans will struggle to operate properly once the PWM drops below a certain duty%.

Finally, make sure your controller and fan circuit are sharing the same ground (not just plugged into the same circuit but literally have their ground planes connected). If they aren't I can almost guarantee that's the problem.

[daplatapus]

Everything looks like it checks out. But it turns out the BC549C can't power up multiple fans so the 2N3904 that is on that schematic Chris shared earlier. There's a thread on ukreefs about it but not sure if I can link it here...

[ScubaSteve]

Originally Posted by daplatapus

Everything looks like it checks out. But it turns out the BC549C can't power up multiple fans so the 2N3904 that is on that schematic Chris shared earlier. There's a thread on ukreefs about it but not sure if I can link it here...

Can you repost the schematic and the link to that thread so I can take a look?

[daplatapus]

Sure
Schematic:



Link: You may have to go back 2 pages I think to where the guy brings up his problem and works through it.

http://ukreefs.com/index.php?topic=605.135


Thanks Chris for the help! Even though I kept you up 'till all hours of the morning on the east coast

[daplatapus]

Hmmm, looking like I have a wee bit of bleed voltage on my OCW string. On one heatsink, one of the OCW all 3 LED's are faintly lit and on the next in the series 2/3 LED's are lit.



Wheeeee, isn't DIY fun!

[daplatapus]

Due to work and a project my wife asked me to do I've not been able to do anything on this project. I've ordered different transistors for the fan circuit and it's on it's way from China...

Pinhead: I tried returning your PM but your box is full.