IntroThe programmable lab power supply JT-DPS5005 from JOY-iT (Elektor part number 18708) is a small module that, with a maximum output voltage of 50 V and 5 A output current, is capable of delivering quite a bit of power, up to 250 W, that is. To make it actually usable an enclosure is also necessary. Here I describe first the assembly into the enclosure, and then usage and testing. In addition to the enclosure, wires, connectors, bolts, a fan, etcetera are also required. For this purpose, JOY-iT can provide the JT-DPS-Case, as an enclosure made to measure (Elektor part number 18709). All the necessary large and small parts are supplied in separate bags: nuts, bolts, plastic stand-offs and nuts, connectors, spade terminals, fan, wires, switch and a small circuit board that supplies the power supply voltage for the fan. This circuit board is mounted on the input connectors; the wires that go to the actual module need to be soldered to this. The spade terminals (which are not insulated) would actually require a special crimp tool, but the thicker wires can also be soldered instead. Of course, the module can also be mounted and used in some other way, but with this enclosure you have everything on hand to build a tidy and safe power supply. Before I started the testing I first built the module into the enclosure from JOY-iT; the module will then have forced-cooling, should that be necessary. However, for the input voltage another power supply source is required. Depending on the application an input voltage of 6 to 55 V can be used; this external power supply has to be capable of supplying at least 5 A (for the maximum output current of 5 A from the module).
First put it together
There are no manuals supplied with either the module or the enclosure. But these can be found on anleitung.joy-it.net. At the time of writing, only a German-language version of the manual for the enclosure was available, JT-DPS-Case-Anleitung.pdf. There is, however, an English-language manual for the module, JT-DPS5005-Manual-3.pdf. The manual for the enclosure only describes the building-in of the larger module (for which the enclosure is intended). The switch I didn't use, the external power supply has its own switch, after all. The power supply connectors (for banana plugs) are firmly attached to the enclosure using the first nut. Then connect the fan to the small circuit board; the plug is not used and needs to be cut off. Strip about 4 mm off the wires and solder these into the corresponding pads, in the rectangle with a small + and – next to it. With a thicker piece of wire connect the two key pads together (if the switch is not used).
Measure the correct length for the thick wires to bridge the distance from the small circuit board to the module. The part of the green connector with the screws can be unplugged from the module; this makes wiring-up much easier. Strip the ends of the wires and solder these into the two large holes in the small circuit board; the one in the corner is minus. After that, the small circuit board can be attached to the back of the two connectors using two nuts. The fan is fastened on the back panel with the four longer screws and 4 nuts, where the nuts are recessed into the housing of the fan. The remainder of the thick wires can be used to connect the output of the module with the two connectors on the front. Strip the ends of the wire that will go into the connector to the module, for a length of about 5 mm and screw these into the green connector. Crimp or solder the two spade terminals to the ends of the two shorter wires that will then go to the connectors on the front panel. The spade terminals are then fastened with two nuts to the connectors on the front panel. Make sure that the four wires are all in their correct places. Better check this once too often. The connections are clearly indicated on the side of the module.
Now the module can be pushed through the front panel and the screw terminals of the connector can be plugged into the module again. With this the assembly is complete, except for attaching the top cover. First, using a lab power supply with a low voltage and current setting, check that the module functions correctly.