| Electronics > Beginners |
| Odd output from Elenco XP-15K Power Supply - Schematic |
| (1/1) |
| tomherrick:
Schematic of XP-15K. |
| tpowell1830:
Hi Tom, you can find your original post by going to the menu above and clicking Profile and then Show Posts. This belongs with your original post. |
| rstofer:
Right, add the schematic as an attachment to the other post and then delete this post (if possible). It's kind of a PITA to flip between two threads to try to follow the schematic versus the PCB images. |
| rstofer:
Diodes D5 and D6 make up a poor man's zener diode and the voltage between ground and the point where the diode connects to R4 should read -1.4, give or take. Black wire of you meter goes on ground. This negative voltage is what allows the regulator to get down to 0V. I don't know the AC voltage between the blue and yellow wires of the transformer but about 1.4 times that value should be measured at pin 3 of the LM317 as a DC voltage. Pin 1 of the LM317 should move between some negative value, like -1.4V, up to some positive value, nearly 15V, but I haven't calculated the exact range. |
| Simon:
Please refer to: https://www.eevblog.com/forum/beginners/odd-output-from-elenco-xp-15k-power-supply/ Tomherrik, this forum does not work like this, you need to post in the original topic or you will just have a bunch of unrelated and unintelligible posts floating around that no one can decipher. You can also edit your post if you want to add information. |
| Navigation |
| Message Index |