Capacitor charging times.
- pre65
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#1 Capacitor charging times.
I'd like to try a DIY capacitor bank between my 15v PSU and the Beresford SEG DAC and see if it's any different to the Dorado PSU enhancer.
The Dorado has (I believe) a current limiter on it's input, so if I use 2 of my Kemet 22000uf 63v low ESR soup can capacitors would I need to do that ?
Also, with my 15v @ 7 amp (max) PSU how long would 2 of 22000uf take to charge up ? Ball park figure would do. I'd probably fit bleeder resistors across the caps unless the brains consider it unnecessary if I turn the PSU off first and the SEG when the light goes out.
The Dorado has (I believe) a current limiter on it's input, so if I use 2 of my Kemet 22000uf 63v low ESR soup can capacitors would I need to do that ?
Also, with my 15v @ 7 amp (max) PSU how long would 2 of 22000uf take to charge up ? Ball park figure would do. I'd probably fit bleeder resistors across the caps unless the brains consider it unnecessary if I turn the PSU off first and the SEG when the light goes out.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- pre65
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#2 Re: Capacitor charging times.
I found an online calculator.
I'll check in my 50W resistor box and then do a calculation.
44000uf - 50R @ 4.5W = approx 6 seconds to get to 14V, peak current 300ma, as an example.
I'll check in my 50W resistor box and then do a calculation.
44000uf - 50R @ 4.5W = approx 6 seconds to get to 14V, peak current 300ma, as an example.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- pre65
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#3 Re: Capacitor charging times.
If I use 25R on each cap then 0-14V = 1.5 secs
25R 9W 600ma peak.
Is that better ?
25R 9W 600ma peak.
Is that better ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#4 Re: Capacitor charging times.
If I remember that supply has a voltage reg followed by a current source, so you won't be comparing like with like.
Than what?Is that better
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- pre65
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#5 Re: Capacitor charging times.
The second example compared to the first example.
ie two caps paralleled with 50R compared with two caps with 25R each.
To be honest I can't hear any difference with ,or without the Dorado. Just wanting to try something a bit different. Unless you think I'm wasting my time ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#6 Re: Capacitor charging times.
Those are two things, but I don't understand what attribute you are using to compare then to make one better than the other.ie two caps paralleled with 50R compared with two caps with 25R each.
All you have is two caps being charged through a 50R resistors and the other the same two caps being charged through 12R5 made up of two 25R resistors in parallel.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
- pre65
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#7 Re: Capacitor charging times.
I have trouble trying to explain what I mean.Nick wrote: ↑Sat Apr 18, 2020 7:40 pmThose are two things, but I don't understand what attribute you are using to compare then to make one better than the other.ie two caps paralleled with 50R compared with two caps with 25R each.
All you have is two caps being charged through a 50R resistors and the other the same two caps being charged through 12R5 made up of two 25R resistors in parallel.
I'll do a diagram to show you what I'm thinking.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
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- pre65
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#8 Re: Capacitor charging times.
If I put a 22000uf cap across the PSU output, but without a limiting resistor, would that damage the capacitor on initial charge up ?
The PSU regulating chip is limited to about 7 amp.
The PSU regulating chip is limited to about 7 amp.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#9 Re: Capacitor charging times.
My point is that "better" is not just a simpls thing, better as in cheaper, better as in more expensive, better as in bigger, better as in smaller. Etc.pre65 wrote: ↑Sat Apr 18, 2020 8:02 pmI have trouble trying to explain what I mean.Nick wrote: ↑Sat Apr 18, 2020 7:40 pmThose are two things, but I don't understand what attribute you are using to compare then to make one better than the other.ie two caps paralleled with 50R compared with two caps with 25R each.
All you have is two caps being charged through a 50R resistors and the other the same two caps being charged through 12R5 made up of two 25R resistors in parallel.
I'll do a diagram to show you what I'm thinking.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#10 Re: Capacitor charging times.
The cap would not care as long as its voltage limit were maintained, don't know if the power supply would like operating into a momentary short though.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
- pre65
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#11 Re: Capacitor charging times.
So,a 1K (for example) resistor across the cap would prevent a momentary short ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#12 Re: Capacitor charging times.
Hmm, a resistor, any resistor in parallel with a s/c is going to do what exactly?
- pre65
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#13 Re: Capacitor charging times.
A resistor across a capacitor will act as a bleeder resistor, and also as a load if the real load (ie my SEG DAC) is not switched on.
So I'm thinking (always dangerous ) that as the capacitor is not a permanent short the resistor will make it not blow up the power supply.
Even as I'm trying to explain things it sounds wrong.
For how long would the capacitor remain a short circuit ? Milli seconds ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- pre65
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#14 Re: Capacitor charging times.
I connected 1 x 22000uf capacitor (without resistor) to the PSU output, then switched the PSU on.
No smoke or any signs of distress.
Next time Jean is out I'll test for sonic changes, although with my aural memory it's doubtful I'd notice anything.
No smoke or any signs of distress.
Next time Jean is out I'll test for sonic changes, although with my aural memory it's doubtful I'd notice anything.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
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#15 Re: Capacitor charging times.
No, on switch-on the cap is just a very low resistance ( eg. the ESR of the cap type ) in parallel with a much larger resistance. the current just surges into the lower resistance (cap) till it's charged-up. The parallel resistor only has purpose when you switch off.
"Once you find out ... the Circumstances ; then you can go out"