This is what it looked like. I was working with this power supply on several projects and all the cables started to anoy me.

Voeding_Before

First I placed some painters tape on the place where the holes were needed. Then I drilled holes for the connectors. With a drill smaller than the connector needed, I made the hole and then held the drill sideways to create a oval shaped hole. The notch of the connector then fitted in the wider part of the oval hole. Crimped some connectors on the correct cables and mounted them to the 4mm connectors.

The end result looks like this:


Ofcourse I tested the voltages to make sure that the label was correct. There is a power good cable which is just sitting there. Maybe I will connect a led to that. Also there is no off switch and the -12 V is missing. I might adjust this later. I did not solder the connections so modification of the power supply is easy.

At the end I think I should have kept the cables a bit longer. Putting on the case is possible, but you need to put some force on the cover to get it to fit.

Disclaimer, these are the colors for my power supply, I cannot guarantee that these are the same with other power supplies.

Color Function
Blue -12V
Black GND
Orange 3.3V
Red +5V
Purple +5V StandBy
Geel +12V
Green PS On
Gray Pwr Ok

Here is the Power supply in all it’s glory. I have mounted it to a piece of MDF, which I put together without any glue :-D. I took a piece of MDF, drilled a few holes in it and from the holes used the jigsaw to make a handle to hold it properly. After that I took a spirit level to guide a router. In the router I used a routingbit with the same diameter as the thickness of the MDF. With the router created a long slot for the other piece of MDF. Then slided the pieces together and this is the result.

The blue box, better seen as a black box is something I cannot tell anything about (yet). It is secret . .. Even the logo which was on there is gone. Isn’t Paint.NET a great tool?! The filename gives a hint, like in an anagram but more I cannot tell about that.

On the MDF I also mounted a WRT54G which is now in use as a DHCP server. With the DD-WRT image on it, the device supports leasing an ip address to a specific MAC address. That way I can use devices in DHCP mode and every time have the same configured IP address. Another advantage is that the WRT54G acts as a router which supports internet access via a wired connection. Here is a video how to open the WRT54G easily:

Instructions for putting on DD-WRT came from this page. It explains in detail the steps to take. I made a copy on this page to make sure I don’t end up with a broken link. I love the work the DD-WRT team has done. Maybe I will also take a look at OpenWRT bcos they are opensource.
Flashing:

  1. Read the peacock announcement found here: http://www.dd-wrt.com/phpBB2/viewtopic.php?t=51486.
    • DO A HARD RESET *BEFORE AND AFTER* YOU CHANGE DD-WRT FIRMWARE VERSIONS. This does not mean hitting the reset button and saying you are done. This means doing the 30-30-30 reset. To do a 30-30-30 reset you must push the reset button with your router powered on. Hold it for 30 seconds with the router powered on. STILL holding it, pull the power cord for 30 seconds. Still holding it, plug the power back into your router and continue to hold the reset button for 30 more seconds. You will have held the button for a full 90 seconds without releasing it.
  2. Do a HARD reset on the router according to note 1 of the peacock announcement (30/30/30).
  3. Set a static IP on your computer to 192.168.1.7. Subnet mask should be 255.255.255.0.
  4. Connect the lan cable from your computer to a LAN port of your router. Make sure your router is plugged in. Nothing should be connected to your computer or the router except the lan cable between them. Turn your firewall and any wireless computer connections OFF.
  5. Power cycle the router (uplug the power from the router for 30 seconds and then plug it back in)
  6. Open your browser to 192.168.1.1 by putting that in the browser address window of your browser. You should open the linksys webgui and NOT a page that says Management Mode. If you see management mode, power cycle the router again.
  7. Leave the username blank and enter “admin” as the password
  8. Go to administration and firmware upgrade
  9. Navigate to the folder that you are using, and select your binfle from http://www.dd-wrt.com/site/support/router-database. I have taken the dd-wrt.v24_std_generic.bin
  10. Hit upgrade
  11. When you get a message that the upgrade is successful, wait FIVE FULL minutes before continuing.
  12. If you don’t get success, repeat from steps 6 up to this one. If you still don’t get success, clear your browser cache. Try using a different browser as well, to navigate to 192.168.1.1.
  13. When you can access the dd-wrt webgui using a browser at 192.168.1.1, power cycle the router.
  14. When you can again access the dd-wrt webgui using a browser at 192.168.1.1, do another HARD reset on the router.
  15. At this point you can choose to put a different build on, depending on what you needs are.
    • Initially I used the version as indicated above, but it was unstable. My ISP provides a download speed of 22 MB, but after a few days, I could not get more than 2 MB. Restarting the router solved this. After I installed a *vintage* build, my router is running stable. Use the VINT version recommended in the peacock announcement.
  16. Reset your computer ethernet connection to auto IP and auto DNS
  17. The hook you see is for attaching all the cables which belong to this set (power cable, network cable, RS232 Null-modem cable etc.)

One thought on “Lab power supply 2.0

  • 2016/01/21 at 18:21
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    Nice tool! The PWR-OK status as you mentioned or even a regular power LED will be quite useful (besides the fan noise as indicator ☺). This is because in case of over-/under-voltage or over-current, one can diagnose the PSU behavior better.

    For example, some power supplies can blink that PWR-OK LED, with the aim to reset a motherboard. However, other PSU’s can power off completely, and act like a fuse was blown. In case this happens, you can easily reset it by power cycling or unplugging from the wall outlet for at least 15 seconds.

    Alternatively, and even better; adding some additional fuses for every output in series also wouldn’t hurt, because you might not want to fully discharge your internal capacitors over the load first. So if you don’t add these fuses, in case of an accidental short the maximum specified current can be theoretically exceed caused by the energy stored in the caps too. Although, I guess that might be some improvement that fits in 3.0 😉

    Reply

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