deandob said:
I've noticed that as well. I think if you look you'll notice a much smaller set of electrolytics, on my board they're a blue/metallic and from BC (Vishay). These are in fact the high ESR "damping caps" that should remain. I think they're valued at 22uF as well.
Cheers,
Chris
It would be good to hear from Jan-Peters directly on this.
I do see the smaller blue caps and checking the connections they are indeed in parallel to the larger supply caps. As this is the case, these caps are probably specifically selected as matched for this circuit to reduce resonances, so should not be touched without mucking up the intended design or unless you have a scope to detect and tune ringing with new caps.
Can anyone report any changes heard when replacing these caps?
Regards,
Dean
I do see the smaller blue caps and checking the connections they are indeed in parallel to the larger supply caps. As this is the case, these caps are probably specifically selected as matched for this circuit to reduce resonances, so should not be touched without mucking up the intended design or unless you have a scope to detect and tune ringing with new caps.
Can anyone report any changes heard when replacing these caps?
Regards,
Dean
Is it possible to place digital circuits close to the UCD module? I was specifically thinking about using a CD4013 D Flip-Flop to toggle an on off push button and a 555 timer for a time delay plus some mosfets to handle the current. My fear is that the UCD will blast the CD4013 with EMI\RFI causing it to change state.
If this is not possible I can revise my whole circuit to work with 6 relays, at a higher cost. I don’t know what happens to reliability.
Leve
If this is not possible I can revise my whole circuit to work with 6 relays, at a higher cost. I don’t know what happens to reliability.
Leve
Hypex softstart backwards?
I finally got my new bigger transformer so I needed to use a softstart. Since I'd liked the other Hypex stuff so much I went ahead and used their softstart.
However it seems to be wired backwards with respect to the switching feature.
I've already got a main switch, but I bought a pushbutton for the front panel. Unfortuantely I didn't have a big enough metal bit to put another hole on the front panel and it wasn't worth a special trip out for a new bit. So since I didn't have a switch I could use I put the jumper for switch and just ran a wire between the two switch contacts (as if the switch was always on). Of course it didn't come on. I kept measuring different points trying to figure it out. Finally on a lark I hooked up a couple of spare LEDs to see what was going on. With that I noticed that it never came out of standby. After I removed the wire between the switch I finally started hearing the relay switch over.
So my question is this, Is this backward style switching common to softstarts or is there some reason Hypex picked it?
I finally got my new bigger transformer so I needed to use a softstart. Since I'd liked the other Hypex stuff so much I went ahead and used their softstart.
However it seems to be wired backwards with respect to the switching feature.
I've already got a main switch, but I bought a pushbutton for the front panel. Unfortuantely I didn't have a big enough metal bit to put another hole on the front panel and it wasn't worth a special trip out for a new bit. So since I didn't have a switch I could use I put the jumper for switch and just ran a wire between the two switch contacts (as if the switch was always on). Of course it didn't come on. I kept measuring different points trying to figure it out. Finally on a lark I hooked up a couple of spare LEDs to see what was going on. With that I noticed that it never came out of standby. After I removed the wire between the switch I finally started hearing the relay switch over.
So my question is this, Is this backward style switching common to softstarts or is there some reason Hypex picked it?
Maybe this was asked later but will it be absolutely safe to use 63V filter caps with Hypex 2x42VAC transformer. This will give about 59VDC and will not quite offer 10% "safe margin".
I do not know if Hypex supplies use 63V caps?
I will kick off Rotel RB1070 from my Orion woofers and make UCD400.
M&T are amplified by UCD180.
I do not know if Hypex supplies use 63V caps?
I will kick off Rotel RB1070 from my Orion woofers and make UCD400.
M&T are amplified by UCD180.
I wonder if you could rig the soft start to use both a button and a remote on feature (using a low voltage connection, like found on many amps and preamps). I'd like to be able to control on/off with a remote. Currently, my amps turn on when I turn on my preamp, and my preamp has many different controls for turning on and off the low voltage connection.
Pasi P said:
I wouldn't. You neglected to subtract the voltage drop of the rectifiers, but then you really have to account for a 10% mains variation, while unloaded (another 5% at least).
You should really be aiming for a safety margin of 20% on your caps, maybe push it to ten, but only after your worst case scenario of 15% overvoltage. Exceeding their limit just once is enough to ruin the sound of your caps, which are usually expensive, and if you're really unlucky they can fail outright.
Pasi P said:
To use 63V caps on a 57-59VDC voltage is NO problem. Don't forget the BCC caps do also has a surge voltage what is 10-15% higher as the rated voltage. We use the BCC caps already for many, many years, and NEVER had one failure.
Caps with failure because of rail voltage what is at the rated voltage will only happen with cheap Chinese manufactured caps. There are a lot of stories known about this.....
Jan-Peter
Indeed! When you have some cheap caps, I would have a voltage difference of at least 20-25%. But with manufacturs like BCC/BHC, you could have a difference of 5-10%.
This counts only for those big snap in capacitors. The smaller caps like 22uF-470uF we use a bigger margin. With a voltage of 65V we use 100V rated capacitors.
Jan-Peter
(inderdaad goede vakantie, en niks gebroken.....
)
This counts only for those big snap in capacitors. The smaller caps like 22uF-470uF we use a bigger margin. With a voltage of 65V we use 100V rated capacitors.
Jan-Peter
(inderdaad goede vakantie, en niks gebroken.....
)Adding zener diodes
Wouldn't simply adding zener diodes either after the diode bridge or after the power supply resolve all the potential issues with over-voltages? My understanding of electronics is feeble at best, but I thought that was the purpose of such beasts, to shunt excess voltage to ground.
Wouldn't simply adding zener diodes either after the diode bridge or after the power supply resolve all the potential issues with over-voltages? My understanding of electronics is feeble at best, but I thought that was the purpose of such beasts, to shunt excess voltage to ground.