I am a rookie at all this DIY stuff. I got my BSEE about 30 years ago and finally am starting to get to use some of what I learned although I must admit the cobwebs are awful thick. To get started I thought I would build someone elses design and settled on the Pass Penultimate Zen. I plan not to make a regulated supply because I have lots of capacitors at my disposal. I will use about 100,000 uf for each channel. When the switch gets turned on those caps look like a dead short across the bridge until they start charging. I notice a CL-60 thermistor in series to limit the in-rush current. My for you more experienced DIYers, my question is this: I would like to add an emi filter to the AC input and I already have one rated for 6 amps. I was wondering what the odds of me cooking the filter and how much does the CL-60 limit the in-rush current to. Thanks to all.
kWski,
Here's a link to the spec sheet on the cl thermistors. It looks as if the max current for the 60 is 5A.
http://www.thermometrics.com/assets/images/cl.pdf
Here's a link to the spec sheet on the cl thermistors. It looks as if the max current for the 60 is 5A.
http://www.thermometrics.com/assets/images/cl.pdf
AF,AudioFreak said:
Yes, I see that now. The 5A max is the steady state current rating of the device.
Here are some previous discussions on this device and other possibilities for limiting inrush.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=8882&highlight=thermistor
http://www.diyaudio.com/forums/showthread.php?s=&threadid=10413&highlight=inrush+cl60+nelson
Gentlemen,
I think I have found a thermistor that will suit my means in limiting the inrush to under 6 Amps. It is made by Ametherm. Here are the specs:
...........................R@25C..........SSI.......Max Joules........R@Hot
MS2230005.............30.0.............5.0.............150................0.230
At 120VAC and 30ohms I would have 4 amps maximum inrush. The thermistor would drop .69 volts and dissipate 2.07 watts when the capacitors are fully charged and the amp draws the max. 3 amps of primary current for the Penultimate Zen.
This this sound right, gents? Or am I too rusty?
I think I have found a thermistor that will suit my means in limiting the inrush to under 6 Amps. It is made by Ametherm. Here are the specs:
...........................R@25C..........SSI.......Max Joules........R@Hot
MS2230005.............30.0.............5.0.............150................0.230
At 120VAC and 30ohms I would have 4 amps maximum inrush. The thermistor would drop .69 volts and dissipate 2.07 watts when the capacitors are fully charged and the amp draws the max. 3 amps of primary current for the Penultimate Zen.
This this sound right, gents? Or am I too rusty?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.