Thanks, @RickRay , but this/my board seems to be malfuncioning, the bulb is fully lit from the moment on I plug it in, and the led-on is on regardless of the switche‘s position. Led-off does not light up…
I believe I‘m in for a fiddling (debugging) session, probably starting with
The thing that baffles me is that the board consistently behaved like this and that there is some functionality (there’s a relay clicking when a power-cut occurs/the rear switch is activated…
I believe I‘m in for a fiddling (debugging) session, probably starting with
- a general inspection for lousy soldering
- misplaced parts
- broken parts according to @Mark Johnson ‘s list mentioned recently, this (#699)
The thing that baffles me is that the board consistently behaved like this and that there is some functionality (there’s a relay clicking when a power-cut occurs/the rear switch is activated…
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I am not sure about this, OmeEd, are you describing how it should work, or is this a debug procedure starting with P6?
It's an minimalist explanation intended to describe why the position of the front switch during power-on matters, (when using a toggle switch for the purpose). This as you observed the circuit automatically passing to the on-state, and imo that's not necessary a fault (when using a toggle switch).
So, if I understand you correctly, I should be a bit more patient and see if it begins to switch after some off-on-off-cycles, beginning with the switch in the off position?
When powering it up with the back-switch while the front-switch is in the off-state, the circuit should start in the in the correct state, namely OFF. Otherwise it would take an on-off cycle to synchronize. Two more remarks.
1. You mention using a bulb, I take it you use it as a load (As substitute for the main transformer). When using it in series with the circuit (some people do this while initial testing an amplifier), it might create problems with SMPS.
2. This circuit works way more elegant when used with a momentary push-button. Why do you insist on using a toggle-switch?
1. You mention using a bulb, I take it you use it as a load (As substitute for the main transformer). When using it in series with the circuit (some people do this while initial testing an amplifier), it might create problems with SMPS.
2. This circuit works way more elegant when used with a momentary push-button. Why do you insist on using a toggle-switch?
Rhank you again, @OmeEd
When I switched it on the first and second time, I indeed used a dim-bulb device in series with the circuit). It went as erwartet: bright on start, dim down to invisible.
(And, to be frank, the first run was with the whole PSU connected, it works)
I then connected H9KPXG directly and used the bulb (40W) as load.
H9KPXG never showed me an off state.
I have the front-plate cut to fit this one form-factor of the switch, out of habit and because of its pleasant look. I‘m already looking for a momentary switch that would fit the slot… (but if it would be working with what I have, I would be happy with that)
When I switched it on the first and second time, I indeed used a dim-bulb device in series with the circuit). It went as erwartet: bright on start, dim down to invisible.
(And, to be frank, the first run was with the whole PSU connected, it works)
I then connected H9KPXG directly and used the bulb (40W) as load.
H9KPXG never showed me an off state.
I have the front-plate cut to fit this one form-factor of the switch, out of habit and because of its pleasant look. I‘m already looking for a momentary switch that would fit the slot… (but if it would be working with what I have, I would be happy with that)
The schematic gives no reason to assume it should not work as intended.
The customary of using an incandescent light bulb as current limiting device for testing remains remarkable, as cold it has lower resistance.
The customary of using an incandescent light bulb as current limiting device for testing remains remarkable, as cold it has lower resistance.
If it were me... It seems the board may be working fine when using the rear switch - that is, relay clicking when that switch is used - then I would move on to working exclusively with the front switch. When the board is turned on, get your multimeter across the light bulb and just make sure you're not sending high current/voltage to the bulb. If all seems well, connect your transformer and try again.
Yes, this is encouraging!
Somewhere in these 39 pages there are two comments I seem to recall. If only I could find them... 1) There may be a minimum voltage needed to get the H9KPXG to work as intended. This is why adding only your transformer might be the right next step. 2) You may need to cycle the H9KPXG a few times before it works as intended. It probably has to do with the logic chips and a couple of capacitors...
EDIT: Found a reference:
https://www.diyaudio.com/community/...ncludes-soft-start-h9kpxg.354971/post-6229775
The picture of the assembled board you posted in #746 reveals that the CD40106 is not correctly inserted in her socket. Pins 1 to 7 are bend outside of the socket.
I got a bit help. Rereading #766 my attention was caught by the 6 word sentence "H9KPXG never showed me an off state", this made the 40106 first in the chain of suspects. It was under active investigation when I spotted the problem. If it proofs anything it's the importance of factual fault reporting and the emergent power rising from a joint effort. Thank you all.
I would like to confirm the board is working.
Haven’t yet put any load on it, just switched it on and it instantly turned on the OFF-led. (With the switch obviously in the open position)
On is on as well, and the relay‘s clicking just as expected…
This was one of my more ridiculous (not hazardous) bungles. (The most idiotic one I keep secret
🤐
)
Again many thanks for all the help and encouraging and support and this project to Mark, OmeEd, RickRay, IAIMH, and the community!
Haven’t yet put any load on it, just switched it on and it instantly turned on the OFF-led. (With the switch obviously in the open position)
On is on as well, and the relay‘s clicking just as expected…
This was one of my more ridiculous (not hazardous) bungles. (The most idiotic one I keep secret
🤐
)
Again many thanks for all the help and encouraging and support and this project to Mark, OmeEd, RickRay, IAIMH, and the community!
With H9KPXG in the off-state, I measure 40VAC on P1D - P2N / 0.1mA, and +6 / -13 VDC / 10mA, the PSU‘s led are dimly on.
This is the normal behaviour as was discussed somewhere up in the thread, and I’m good, correct?
This is the normal behaviour as was discussed somewhere up in the thread, and I’m good, correct?
Under 'switched off' condition (rear switch on, front switch off) the circuit is not actually off but on standby.
Mains inlet P2-2 is always connected to P11-4
Mains inlet P2-1 is always connected to P11-1 by the series connection of ICL1, C3 and R7.
Ergo, when the system is in standby you will measure an AC voltage between P11-1 and P11-4, the value of which differs depending on whether or not a transformer is connected.
The voltages present at P2 and P11 are potentially fatal, so it is better to stay away from them even during standby.
For the record; assuming 230V mains voltage and a transformer with a single primary winding of 230V, P8, P9 and P10 are empty, the primary winding is connected between P11-1 and P11-4, and the light bulb is in the trash.
Mains inlet P2-2 is always connected to P11-4
Mains inlet P2-1 is always connected to P11-1 by the series connection of ICL1, C3 and R7.
Ergo, when the system is in standby you will measure an AC voltage between P11-1 and P11-4, the value of which differs depending on whether or not a transformer is connected.
The voltages present at P2 and P11 are potentially fatal, so it is better to stay away from them even during standby.
For the record; assuming 230V mains voltage and a transformer with a single primary winding of 230V, P8, P9 and P10 are empty, the primary winding is connected between P11-1 and P11-4, and the light bulb is in the trash.
I'll be using an H9KPXG for my BA2018 build. I'll also be using a Muses MCU which includes some power on/power off features of it's own. Since the MCU allows for turn on by remote or front panel button, I'd like to have both options available. That is, with the MCU triggering the H9KPXG either through the front panel switch or the Muses remote control.
The only option for the MCU to control anything downstream is to use a specific "test point" which, according to Academy Audio, "...goes high (+5V) a few seconds after the MUSES system turns on and goes low immediately when the system turns off or goes into a Standby mode."
So this seems like the correct connection between the MU and the H9KPXG, but I am pretty sure I don't need to supply +5Vdc to the H9KPXG switch, I just need to enable the electrical connection between the two terminals at P1. For safety, an optocoupler or relay circuit to isolate the MCU from the H9KPXG seems right, too.
I could build or buy a 5V single-channel relay circuit. Does this seem like I'm heading in the right direction?
(And in the chicken/egg part of this, the MCU will obviously need some kind of trickle voltage to be able to sense that the remote or front panel button are being activated. Hmm. Maybe the 5V_HOT could solve this?)
I think I'm part way there, but seeking a bit of guidance. Thanks.
The only option for the MCU to control anything downstream is to use a specific "test point" which, according to Academy Audio, "...goes high (+5V) a few seconds after the MUSES system turns on and goes low immediately when the system turns off or goes into a Standby mode."
So this seems like the correct connection between the MU and the H9KPXG, but I am pretty sure I don't need to supply +5Vdc to the H9KPXG switch, I just need to enable the electrical connection between the two terminals at P1. For safety, an optocoupler or relay circuit to isolate the MCU from the H9KPXG seems right, too.
I could build or buy a 5V single-channel relay circuit. Does this seem like I'm heading in the right direction?
(And in the chicken/egg part of this, the MCU will obviously need some kind of trickle voltage to be able to sense that the remote or front panel button are being activated. Hmm. Maybe the 5V_HOT could solve this?)
I think I'm part way there, but seeking a bit of guidance. Thanks.
