Author Topic: Be aware: Yihua YH-305D bench PSU  (Read 89929 times)

0 Members and 1 Guest are viewing this topic.

Offline razvitm

  • Newbie
  • Posts: 2
Re: Be aware: Yihua YH-305D bench PSU
« Reply #50 on: December 30, 2014, 04:04:23 pm »
schematic of a 305D ... any mod suggestions?

i have a power source just like this one, but i don't know where the wires from the knobs go. 2 voltage and 2 current knobes. where do i connect them? can someone please draw the wires on the schematic please?
 

Offline LEDAero

  • Regular Contributor
  • *
  • Posts: 77
  • Country: nz
Re: Be aware: Yihua YH-305D bench PSU
« Reply #51 on: January 15, 2015, 08:11:44 am »
Honestly not sure if it was from the drop or not...

It was.
 

Offline alex27riva

  • Contributor
  • Posts: 8
Re: Be aware: Yihua YH-305D bench PSU
« Reply #52 on: December 27, 2015, 09:47:11 pm »
Since the volts reading is stable it suggests the output current is also stable but the meter is faulted, likely the IC itself in the module.

To confirm this, attach a good ammeter to the output and adjust the current.  You should see the good ammeter read linearly as you adjust up and down while the PSU ammeter reads all over the place.  Short circuit the output, and the CC LED should light, a final note that the current module is working by testing the short circuit protection.

If the above works, then its easiest to replace the ammeter module rather than repairing it.

Hi, how can i fix this problem?

Same problem again, maybe the cold weather?
 

Offline Shock

  • Super Contributor
  • ***
  • Posts: 3605
  • Country: au
Re: Be aware: Yihua YH-305D bench PSU
« Reply #53 on: December 28, 2015, 11:37:48 am »
As mentioned an intermittent/dry solder joint or problematic connector. Capacitors failing with high ESR can be the cause of cold failures as the colder they are the higher the ESR.
Soldering/Rework: Pace ADS200, Pace MBT350
Multimeters: Fluke 189, 87V, 117, 112   >>> WANTED STUFF <<<
Oszilloskopen: Lecroy 9314, Phillips PM3065, Tektronix 2215a, 314
 

Offline bob808

  • Regular Contributor
  • *
  • Posts: 131
  • Country: 00
Re: Be aware: Yihua YH-305D bench PSU
« Reply #54 on: August 26, 2016, 07:05:27 pm »
I have the Zhaoxin RXN-305D variant.
Has anyone added a sense wire circuit into these power supplies?
 

Offline bitseeker

  • Super Contributor
  • ***
  • Posts: 8914
  • Country: us
  • Lots of engineer-tweakable parts inside!
Re: Be aware: Yihua YH-305D bench PSU
« Reply #55 on: August 26, 2016, 11:45:20 pm »
bob808, can you attach some more pics of the PCBs at higher resolution?
TEA is the way.
 

Offline GigaJoe

  • Frequent Contributor
  • **
  • Posts: 307
  • Country: ca
Re: Be aware: Yihua YH-305D bench PSU
« Reply #56 on: October 31, 2016, 02:42:11 am »
Wonderful ..... 30 VAC ( 5 ??) between ground and a negative or positive output, regardless PS on or off ... Just fry my circuit, detached just a positive and left a negative wire, touch by soldering tip  (it grounded) .... oops ... 
 

Offline GigaJoe

  • Frequent Contributor
  • **
  • Posts: 307
  • Country: ca
Re: Be aware: Yihua YH-305D bench PSU
« Reply #57 on: March 13, 2017, 04:11:47 am »
Finally, look inside,  The problem with 30V AC on output , was due to power switch disconnect a ground wire, not a hot wire , so the hot wire over transformer and so induced that 30V on output. Changing wire on power socket solved it ...

 

Offline bitseeker

  • Super Contributor
  • ***
  • Posts: 8914
  • Country: us
  • Lots of engineer-tweakable parts inside!
Re: Be aware: Yihua YH-305D bench PSU
« Reply #58 on: March 13, 2017, 04:25:58 am »
Wow, that was a nasty one. Good thing you found and fixed the source.
TEA is the way.
 

Offline minicowman

  • Newbie
  • Posts: 1
  • Country: us
  • But, if I type personal text, won't other see it?
    • Southeast Nebraska Ham Radio and Electronics
Re: Be aware: Yihua YH-305D bench PSU
« Reply #59 on: March 05, 2019, 05:09:40 pm »
You showed the better part of a schematic for one of the Chinese power supplies (305D).. Some of it was cut off.  Just wondering if I could get a look at the rest of the schematic. Or, if there is more documentation on this.. What you had posted is the most I had found on these to date.  Thanks.
“I have never let my schooling interfere with my education.”
― Mark Twain
 

Offline henryinsydney

  • Contributor
  • Posts: 9
  • Country: au
Re: Be aware: Yihua YH-305D bench PSU
« Reply #60 on: May 30, 2021, 12:12:11 pm »
Thanks a lot for the schematics! This is really close to my WEP 305D if not the same board. I was about to reverse engineer it but there are about 80 components on the board (single sided, though), still an onerous job.
Mine just stopped putting out any voltage/current and even said so on the LEDs.. no matter what the dials were set to.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf