Thanks for sharing. I use it as stabilized screen supply for push-pull 7189 pentode stereo amplifier. 300 V, 10-50 mA. Removed unnecessary bulky parts: fuse holder (replace with 40 AWG jumper wire), screw terminals, LED, trim pot (replace with 2.2K resistor), all electrolyte caps (bad quality indeed). In freed-up space added 10 uF stack of ceramic wafer filter caps, 1 mH iron powder core filter toroid, and 10 uF 450 V Nichicon second filter cap. Plus additional outboard LC filtering element. The module screwed to aluminum chassis by heat sink, with thermal paste between sink and chassis - for better cooling.
Hi Anatoly, Thankyou! Yes as I said its some Work necessary to get these Modules output "Cleaner". I would be interested to see how the 10uf Stack of Ceramics look ! What additional LC Filtering element you men/use ? My Email is in the Channel Description Tab. Cheers, Konstantin
@@KonstantinGrigoriadis My first interrest goes for the hv module. Reusing the parts for a better module with real world specoifications (without the need to cool it down to near zero Kelvin like Ali express does it). I am interested in getting the ripple voltage down to a minimum.
High Tony, the Transformer uses an EFD25/13/9 Core that will deliver Max ca. 20W(according to Magnetics Datasheet), that probably was intended for a Capacitor Charger for Photography Studio Flash(my Assumption :-). The Transformer gets Warm when these max 20W are exceeded and bcs the transformer is probably not designed to work with a duty Cycle more then 50%, which is the case using the UC3843 Chip that goes up to almost 100% Duty. In my Redesign of the Module for the Capacitor Leakage Tester, I will never reach these 20W. The most important is to not exceed those 20 W (the Magnetic Datasheet states it even for less 18W) and to use higher Input Voltage (19-24V Laptop PSU), to keep the Duty Cycle as near as Possible to 50% by using the Whole Secondary Winding instead only the Half ! Cheers, Konstantin
Got this module for testing transistors for their avalanche properties (for a Jim Williams fast edge pulse generator) works nice, I only used up to 250v. Just I'll be adding a filter on the output, something at least 22uH inductor and a second capacitor, probably a few ceramics too, I don't need a lot of juice but lower noise will be nice, I didn't measured the noise but probably be way more than 10Vpp.
Hi Ruben, the LC lowpass is nessesary , I would suggest additionally a ferrite bead 1000ohm@100Mhz followed by a 10nf HV Ceramic. This Module IS noisy :-)
The sense on the cs pin is to limit the current cycle by cycle as a part of the Regulation, the sensing via the 393 is used to Shut it complete down in a ocp situation like a crowbar, donno why they did it so, its redundant .
I bought one such power supply. I plugged it in, started testing it, got to 200 volts and the board died. I only needed it for an experiment. The microchip uc3843 does not last 2 minutes of operation. I'm going to gut the board, keep only the feedback connections for the comparators, leave the power part and graft a tl494. I hope it lasts half an hour to get my work done...
Hello, with what voltage you powered the Module and what Load you used ? Normally these things work ok when used in their real limits, except if you had faulty module. To use the tl494 it must be configured as a single output for a flyback . The tl494 has no advantage in this circuit as a flyback over the uc3843. The comparators are used for Over voltage and Overcurrent . Cheers, Konstantin
@@KonstantinGrigoriadis I tried powering a small neon lamp (about 90 volts) through a 1 megohm resistor. The supply voltage of the module was 12 volts. Even the LED indicator on the module burned out. There is supply voltage on the LED pins, but the LED has gone. I have quite a 16 pin tl494, it has built in comparators. If I like the Frankenstein that will result between the TL and the module, I might consider factory pcbs. :)
I have used one of these modules for a stereo PCL86 amplifier. 13V for the filament and for the converter. But I don't trust it much. The transformer gets very hot. I think its at the limit it can handle. I disabled the negative rail output on mine: it had less power capability than the positive out, anyway. And when I draw power from the positive out, the negative rail was climbing in voltage as it stayed unloaded, fearing capacitor explosion. I think the transformer could be replaced by a more powerful one from an old smps, but used backwards?? One from a 12v 60+ watts?
Hello Josep, The Transformer uses an EFD25/13/9 Core that will deliver Max ca. 20W(according to Magnetics Datasheet), that probably was intended for a Capacitor Charger for Photography Studio Flash(my Assumption :-). The Transformer gets Warm when these max 20W are exceeded and bcs the transformer is probably not designed to work with a duty Cycle more then 50%, which is the case using the UC3843 Chip that goes up to almost 100% Duty. In my Design I don't use the CT of the Secondary, I use the Sec in Total. As for more Power, I would make a new Design with a better Transformer made on my specs in China. I don't use Salvaged Transformers that are not available en mass(like the one of the Module, or on other Widely available Modules), bcs this makes it a one of project and I want my Designs repeatable. But for a on off project the salvaged one would do, although UN-optimized and the SMPS from where you use the transformer must be a Flyback one(Laptop PSU for ex.), PC PSU' are mostly HalfBridge Designs or Better. To get 300V and above I would use available (what I will show in a future Video) Aliexpress transformers for PushPull Operation >= 100W. Flyback is noisy, I prefer PushPull for Audio and RF when i need to Power HV equipment from Low Voltage. Cheers, Konstantin
Nice project. Are there terminals/connector to read the scaled output voltage setting and cap leakage current? I was looking for something around the volt set potentiometer. I am thinking it would be nice to use the cheap Chinese LED voltmeter modules to display output voltage and current.
Hi Darren, Thankyou! The Modules of the Video are just the HV Flyback Converters for the Future Cap Leakage Design which will be MCU based and display both Set Voltage and Leakage at the Set Voltage on a LCD Display. The Cap Leakage Tester will have switchable: 1) a 12 Pos Switch forming a Voltage Divider String for standard High Voltages 2) a 10Turn Pot to set the High Voltage Freely 2) a 12 Pos Switch forming a Voltage Divider String for standard Low Voltages < 50V or so Cheers, Konstantin
Hello, I can send you the Design Files (Gerbers, Bom, Schematic) via Mail. My Email is in the Description of my Channel. Please bear in mind that my Design was made for a High Voltage Capacitor tester, hence the Output Capacitor is only 1uF 1KV. You would nee to change that if you need Higher Current.
@@cslim3881 scroll down to channel Details, you MUST be logged in to see the Email, or try to write here your email not in clear text bcs youtube will delete the comment.
@@KonstantinGrigoriadis CHEAP BASTARDS, that is why :) I have no idea, and although trivial, I still would love to know, as even back then slope compensation was very well known.
Thanks for sharing. I use it as stabilized screen supply for push-pull 7189 pentode stereo amplifier. 300 V, 10-50 mA. Removed unnecessary bulky parts: fuse holder (replace with 40 AWG jumper wire), screw terminals, LED, trim pot (replace with 2.2K resistor), all electrolyte caps (bad quality indeed). In freed-up space added 10 uF stack of ceramic wafer filter caps, 1 mH iron powder core filter toroid, and 10 uF 450 V Nichicon second filter cap. Plus additional outboard LC filtering element. The module screwed to aluminum chassis by heat sink, with thermal paste between sink and chassis - for better cooling.
Hi Anatoly, Thankyou! Yes as I said its some Work necessary to get these Modules output "Cleaner". I would be interested to see how the 10uf Stack of Ceramics look ! What additional LC Filtering element you men/use ? My Email is in the Channel Description Tab. Cheers, Konstantin
The jumper wire being melted and blown could make more problems than a high current )
look forward to your design.
Which one ? My Version of the hv module or the capacitance leakage tester ?
@@KonstantinGrigoriadis My first interrest goes for the hv module. Reusing the parts for a better module with real world specoifications (without the need to cool it down to near zero Kelvin like Ali express does it). I am interested in getting the ripple voltage down to a minimum.
High Tony, the Transformer uses an EFD25/13/9 Core that will deliver Max ca. 20W(according to Magnetics Datasheet), that probably was intended for a Capacitor Charger for Photography Studio Flash(my Assumption :-).
The Transformer gets Warm when these max 20W are exceeded and bcs the transformer is probably not designed to work with a duty Cycle more then 50%, which is the case using the UC3843 Chip that goes up to almost 100% Duty.
In my Redesign of the Module for the Capacitor Leakage Tester, I will never reach these 20W. The most important is to not exceed those 20 W (the Magnetic Datasheet states it even for less 18W) and to use higher Input Voltage (19-24V Laptop PSU), to keep the Duty Cycle as near as Possible to 50% by using the Whole Secondary Winding instead only the Half !
Cheers,
Konstantin
Hello from Ottawa, Ontario, Canada!
Hi Luc, Greetings from Austria/Vienna
Got this module for testing transistors for their avalanche properties (for a Jim Williams fast edge pulse generator) works nice, I only used up to 250v. Just I'll be adding a filter on the output, something at least 22uH inductor and a second capacitor, probably a few ceramics too, I don't need a lot of juice but lower noise will be nice, I didn't measured the noise but probably be way more than 10Vpp.
Hi Ruben, the LC lowpass is nessesary , I would suggest additionally a ferrite bead 1000ohm@100Mhz followed by a 10nf HV Ceramic. This Module IS noisy :-)
Why have 2 different current sensing, the chip ISence, and the slowish LM393 output???
The sense on the cs pin is to limit the current cycle by cycle as a part of the Regulation, the sensing via the 393 is used to Shut it complete down in a ocp situation like a crowbar, donno why they did it so, its redundant .
@@KonstantinGrigoriadis Oh really! :) Of course they, and I and once again spoke too soon and failed to engage my brain!.
I bought one such power supply. I plugged it in, started testing it, got to 200 volts and the board died. I only needed it for an experiment. The microchip uc3843 does not last 2 minutes of operation. I'm going to gut the board, keep only the feedback connections for the comparators, leave the power part and graft a tl494. I hope it lasts half an hour to get my work done...
Hello, with what voltage you powered the Module and what Load you used ?
Normally these things work ok when used in their real limits, except if you had faulty module. To use the tl494 it must be configured as a single output for a flyback . The tl494 has no advantage in this circuit as a flyback over the uc3843. The comparators are used for Over voltage and Overcurrent . Cheers, Konstantin
@@KonstantinGrigoriadis I tried powering a small neon lamp (about 90 volts) through a 1 megohm resistor. The supply voltage of the module was 12 volts.
Even the LED indicator on the module burned out. There is supply voltage on the LED pins, but the LED has gone.
I have quite a 16 pin tl494, it has built in comparators.
If I like the Frankenstein that will result between the TL and the module, I might consider factory pcbs. :)
Would also be a fine anode voltage supply for a tube circuit.
Yes but with additional Filtering only.
Very good project. I used that module in my own cap leakage tester, but have really not trusted these modules too much 😊
I have used one of these modules for a stereo PCL86 amplifier. 13V for the filament and for the converter.
But I don't trust it much. The transformer gets very hot. I think its at the limit it can handle.
I disabled the negative rail output on mine: it had less power capability than the positive out, anyway. And when I draw power from the positive out, the negative rail was climbing in voltage as it stayed unloaded, fearing capacitor explosion.
I think the transformer could be replaced by a more powerful one from an old smps, but used backwards?? One from a 12v 60+ watts?
Hello, Thankyou, this is why I designed my own Modules using the Transformer and even the Heatsink of the China Modules :-)
Cheers,
Konstantin
Hello Josep, The Transformer uses an EFD25/13/9 Core that will deliver Max ca. 20W(according to Magnetics Datasheet), that probably was intended for a Capacitor Charger for Photography Studio Flash(my Assumption :-).
The Transformer gets Warm when these max 20W are exceeded and bcs the transformer is probably not designed to work with a duty Cycle more then 50%, which is the case using the UC3843 Chip that goes up to almost 100% Duty.
In my Design I don't use the CT of the Secondary, I use the Sec in Total. As for more Power, I would make a new Design with a better Transformer made on my specs in China. I don't use Salvaged Transformers that are not available en mass(like the one of the Module, or on other Widely available Modules), bcs this makes it a one of project and I want my Designs repeatable.
But for a on off project the salvaged one would do, although UN-optimized and the SMPS from where you use the transformer must be a Flyback one(Laptop PSU for ex.), PC PSU' are mostly HalfBridge Designs or Better.
To get 300V and above I would use available (what I will show in a future Video) Aliexpress transformers for PushPull Operation >= 100W. Flyback is noisy, I prefer PushPull for Audio and RF when i need to Power HV equipment from Low Voltage.
Cheers, Konstantin
Nice project. Are there terminals/connector to read the scaled output voltage setting and cap leakage current? I was looking for something around the volt set potentiometer. I am thinking it would be nice to use the cheap Chinese LED voltmeter modules to display output voltage and current.
Hi Darren, Thankyou! The Modules of the Video are just the HV Flyback Converters for the Future Cap Leakage Design which will be MCU based and display both Set Voltage and Leakage at the Set Voltage on a LCD Display.
The Cap Leakage Tester will have switchable:
1) a 12 Pos Switch forming a Voltage Divider String for standard High Voltages
2) a 10Turn Pot to set the High Voltage Freely
2) a 12 Pos Switch forming a Voltage Divider String for standard Low Voltages < 50V or so
Cheers, Konstantin
@@KonstantinGrigoriadis I look forward to the finished design. It is something that I have wanted to build for a long time.
How can I buy your stable 1kv PCB?
Hello, I can send you the Design Files (Gerbers, Bom, Schematic) via Mail. My Email is in the Description of my Channel.
Please bear in mind that my Design was made for a High Voltage Capacitor tester, hence the Output Capacitor is only 1uF 1KV. You would nee to change that if you need Higher Current.
Sorry, not able to locate your email. @@KonstantinGrigoriadis
Click on my channel description that ends with ">" or "...more" to open the About section.
@@cslim3881 scroll down to channel Details, you MUST be logged in to see the Email, or try to write here your email not in clear text bcs youtube will delete the comment.
I have always been disappointed/baffled that the UC384x series does not have built in slope compensation, ....VERY ANNOYING!
Donno Why they left it out
@@KonstantinGrigoriadis CHEAP BASTARDS, that is why :)
I have no idea, and although trivial, I still would love to know, as even back then slope compensation was very well known.