Howdy!
I have my soft start board mostly built, but am weighing options for C2. I have a 1uF on order, but I'm hoping to use one soft start to feed to two 600VA transformers and a power supply capacitance of 240kuF. Since I'm on 120VAC it looks like 0.68uF is probably the best compromise, and maybe I should order that and chuck the 1uF I ordered into the spares bin. Is that right?
I'll be using the back panel kit from the DIYAudio store, which includes a power switch and fuse in the IEC input. If I use that switch I will not run anything into SW1 of the soft start, and put the output of the power switch into SW2, is that right? And I'd omit C1? Does another safety cap need to go earlier in my chain?
What do you think? Anything I'm missing? Thanks!
I have my soft start board mostly built, but am weighing options for C2. I have a 1uF on order, but I'm hoping to use one soft start to feed to two 600VA transformers and a power supply capacitance of 240kuF. Since I'm on 120VAC it looks like 0.68uF is probably the best compromise, and maybe I should order that and chuck the 1uF I ordered into the spares bin. Is that right?
I'll be using the back panel kit from the DIYAudio store, which includes a power switch and fuse in the IEC input. If I use that switch I will not run anything into SW1 of the soft start, and put the output of the power switch into SW2, is that right? And I'd omit C1? Does another safety cap need to go earlier in my chain?
What do you think? Anything I'm missing? Thanks!
Yeah there isn't really anywhere else for it to go between the softstart and the switch. Is it ok to put it straight across the pins of the switch output?
Should I even try using this 1uF cap u ordered for C2, or since I'm feeding 249kuF of PSU capacitance I should probably go straight to 0.68 in the snubber?
I am not sure wether I understand this...
6L6 placed the safety cap at the connector-block (together with the CL60 for inrush-current-limit), I placed it right at the iec-connectors.
As for the snubber-caps, I really don’t know about the value. We‘re supposed to adjust it according to the quasimodo-jig, and was lucky and found the value for my tranny in the quasimodo-results-thread and went with them, no measurement done (blind faith[emoji51])
6L6 placed the safety cap at the connector-block (together with the CL60 for inrush-current-limit), I placed it right at the iec-connectors.
As for the snubber-caps, I really don’t know about the value. We‘re supposed to adjust it according to the quasimodo-jig, and was lucky and found the value for my tranny in the quasimodo-results-thread and went with them, no measurement done (blind faith[emoji51])
Ah, the confusion is my fault, but it actually lead to this helpful information about the quasimodo jig anyways, so thank you! I was not clear that I was asking about two different caps. The snubber I was asking about choosing the value for is C2 on the soft start BOM and C9 in the build guide. Based on the soft start build guide document I believe 0.68uF is the best choice for me, since I'm on 120VAC mains and am feeding a total 240kuF PSU capacitance. I had already ordered a 1uF cap for C2 and was wondering if it was even worth trying, but I think I'll go ahead an order a 0.68uF cap per the build guide.
Struggling to understand the wiring of this board as it relates to the PCB pads.
The power switch in my F6 is a DPST to switch both the 120V and neutral.
With the soft start board I was just going to take the "cold side" of the DPST switch to the PCB.
I am unclear on what the purpose of the C1 cap is that is going across the 120V switch, seems to just make the wiring messier.
I was going to keep the 0.033uF cap in my existing PSU that goes from 120V to neutral.
The power switch in my F6 is a DPST to switch both the 120V and neutral.
With the soft start board I was just going to take the "cold side" of the DPST switch to the PCB.
I am unclear on what the purpose of the C1 cap is that is going across the 120V switch, seems to just make the wiring messier.
I was going to keep the 0.033uF cap in my existing PSU that goes from 120V to neutral.
Hi Chris
I was waiting to see if one of the masters would chime in...
I went the same route as you did with a DPST switch. Both live and neutral come from the switch into the board's neutral and live/sw1. Capacitor is here although I believe it's doing nothing since SW2 is not used.
I most probably won't be able to properly answer questions going further than that, I'm just happy I got mine to function.
The board works perfectly.
hth
david
I was waiting to see if one of the masters would chime in...
I went the same route as you did with a DPST switch. Both live and neutral come from the switch into the board's neutral and live/sw1. Capacitor is here although I believe it's doing nothing since SW2 is not used.
I most probably won't be able to properly answer questions going further than that, I'm just happy I got mine to function.
The board works perfectly.hth
david
C9??
Hi there
,
Sorry but I could not locate a C9 in your schematic.
Is there a latest schematic somewhere and could you kindly point me to it please?
Hi there
,Sorry but I could not locate a C9 in your schematic.
Is there a latest schematic somewhere and could you kindly point me to it please?
Hello!
I´m building a Zon of zen amp by Nelson Pass with two 1kva toroidal transformers and a total of 320kuF in power supply.
Would this soft start circuit handle the inrush current of this?
The rail voltage will be +-44volts, and therefore the continue current draw will be around 1400 watts with 230vac here in Norway.
Thank you very much for reply!
Best regards,
Svein Egil.
I´m building a Zon of zen amp by Nelson Pass with two 1kva toroidal transformers and a total of 320kuF in power supply.
Would this soft start circuit handle the inrush current of this?
The rail voltage will be +-44volts, and therefore the continue current draw will be around 1400 watts with 230vac here in Norway.
Thank you very much for reply!
Best regards,
Svein Egil.
I am about to order the parts for this from Mouser and of course some of the original BoM parts are unavailable. Most were easy enough to determine substitutes, but I want to double check my selection for the relay.
The original BoM called for a 653-G5LA-14-CF-DC24 which is now EoL (End of Life) and unavailable.
I found an updated BoM which lists a G5LE-14-DC24 as a substitute, which is now on back-order (52 weeks).
I searched for a similar part on Mouser and found a 653-G5LE-14-36DC24 that is available and seems to be a good substitute, but not being well versed in deciphering manufacturer's model numbers, I am unsure of the addition of the "36" in the product code.
The closest guess I could come up with was the one I linked above has a Power Consumption rating of 360 mW, and the other two listed are 400 mW. This may not even be the difference, I was just going by both numbers have a 36.
Just want to make sure I am not overlooking something more meaningful before hitting the order button.
The original BoM called for a 653-G5LA-14-CF-DC24 which is now EoL (End of Life) and unavailable.
I found an updated BoM which lists a G5LE-14-DC24 as a substitute, which is now on back-order (52 weeks).
I searched for a similar part on Mouser and found a 653-G5LE-14-36DC24 that is available and seems to be a good substitute, but not being well versed in deciphering manufacturer's model numbers, I am unsure of the addition of the "36" in the product code.
The closest guess I could come up with was the one I linked above has a Power Consumption rating of 360 mW, and the other two listed are 400 mW. This may not even be the difference, I was just going by both numbers have a 36.
Just want to make sure I am not overlooking something more meaningful before hitting the order button.
Hello,
I am unsure whether this should be in the F4 thread, the Universal PSU thread, or here.
I am building a platform for the lower power First Watt amps, but also want it to be able to handle an F5T. Currently it has the F4 boards in it, and a 36V CT transformer inside; specifically the AN4218. My PSU caps are 40V 22,000uF and there are eight, for a total of 176,000uF. Originally I used a NTC thermistor for inrush current as suggested, but it literally exploded. At the time I was using a Hammond transformer, learned about power factor... it pulls 8A from the wall. Oof. Bought the Antec after learning that.
So I built a soft start board and it blew fuse after fuse with the new Antec transformer. I simulated the soft start board (minus the .0033 line cap) and PSU in Micro Cap 12 and it suggests my fuse current would be under the curve shown on the datasheet. I tried lowering C2 to .47uF and it still blows fuses. The max my rails charge to is about 10V before the fuses blow. I don't fully trust the simulation, sometimes .47uF would turn on the circuit, sometimes not. There is always a 4.6A spike at the fuse when the relay turns on, even if I lower the total PSU capacitance to a measly 4,000uF.
I've tried simulating different cap values for C2 & 3, but it suggests there will always be a 4.6A spike. Not trusting the simulation entirely (but nothing at all seems wrong, I've poured over it for countless hours) I have tried a few different cap values for the soft start board and it blows the fuse every time.
I've been trying to figure this out for probably 2 months now and I am utterly out of ideas save for designing my own linear turn on circuit using mosfets, which will take a long time. I simply do not understand how people use this amp. I understand I am over spec on the PSU capacitance, but considering I am using a much more robust solution for inrush current than an NTC thermistor (namely the Soft Start V3), I would expect it to work.
TL;DR, I am using the specified values for everything in the F4 and Soft Start v3 save for the PSU caps: 22KuF @ 8x, using Soft Start v3 w/ C2 @ .47uF (originally 1uF), only charges rails to 10V before fuse blows.
Any help would be greatly appreciated.
Thanks!
I am unsure whether this should be in the F4 thread, the Universal PSU thread, or here.
I am building a platform for the lower power First Watt amps, but also want it to be able to handle an F5T. Currently it has the F4 boards in it, and a 36V CT transformer inside; specifically the AN4218. My PSU caps are 40V 22,000uF and there are eight, for a total of 176,000uF. Originally I used a NTC thermistor for inrush current as suggested, but it literally exploded. At the time I was using a Hammond transformer, learned about power factor... it pulls 8A from the wall. Oof. Bought the Antec after learning that.
So I built a soft start board and it blew fuse after fuse with the new Antec transformer. I simulated the soft start board (minus the .0033 line cap) and PSU in Micro Cap 12 and it suggests my fuse current would be under the curve shown on the datasheet. I tried lowering C2 to .47uF and it still blows fuses. The max my rails charge to is about 10V before the fuses blow. I don't fully trust the simulation, sometimes .47uF would turn on the circuit, sometimes not. There is always a 4.6A spike at the fuse when the relay turns on, even if I lower the total PSU capacitance to a measly 4,000uF.
I've tried simulating different cap values for C2 & 3, but it suggests there will always be a 4.6A spike. Not trusting the simulation entirely (but nothing at all seems wrong, I've poured over it for countless hours) I have tried a few different cap values for the soft start board and it blows the fuse every time.
I've been trying to figure this out for probably 2 months now and I am utterly out of ideas save for designing my own linear turn on circuit using mosfets, which will take a long time. I simply do not understand how people use this amp. I understand I am over spec on the PSU capacitance, but considering I am using a much more robust solution for inrush current than an NTC thermistor (namely the Soft Start V3), I would expect it to work.
TL;DR, I am using the specified values for everything in the F4 and Soft Start v3 save for the PSU caps: 22KuF @ 8x, using Soft Start v3 w/ C2 @ .47uF (originally 1uF), only charges rails to 10V before fuse blows.
Any help would be greatly appreciated.
Thanks!
I've been a massive bingus. I was shorting my rectifier on the negative portion of the mains input. Instead of connecting my centertap to AC1A/AC2A, I was connecting them directly to ground on the capacitor side. Leaving this up in case any fellow binguses encounter my issues.