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Drawing more than 600 mA, while possible with a larger transformer, is not recommended, as there is inadequate heatsinking on a number of components, and the electrolytic capacitors are much too close to the heatsinks.
Another factor limiting the maximum current that can be drawn from the unit is the size of the heatsink. With 600 mA being drawn, each regulator can easily be dissipating 6 watts, and will require a heatsink with a rating of 12°C/W or better to operate in an ambient of 25°C. As heat in an enclosed space may well be greater than this, I'd recommend going for the best heatsink of the correct profile you can get. Hobby shops in Australia have them available at 8.5°C/W (50 mm) and 11°C/W (40 mm), depending on the shop, though I have used 63 mm heatsinks I salvaged from old switch-mode power supplies. The profile used is simply listed as PCB mount
As a note of interest, the prototype was tested running from a HP printer line-lump with a 10v-0-10v coil, the supply outputting +/-12 volts for driving Eurorack modules.
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* If using +/- 18 volt regulators you may need to use 50 volt electrolytics, as depending on your chosen transformer, the rectified DC may be too close to the limit of 35 volt electrolytics for comfort.
* Can this PCB be used with a conventional AC-wall-wart (two AC wires out)? A center tapped transformer is better, though it is possible to use a wall-wart between CT (the 0V connection on the PCB) and one 18V AC connection. The required pads are marked with large white circles. The result will be half wave rectification. If you use larger caps (3300uf) and limit the loading, you will be okay. My test bench power supply had been running like this for years. Watch the output with a CRO if you can, to find the limit. If you really wanted to, two wall-warts could be used, each between one of the 18V connections, and commoned at the CT connection. You'd have to make sure the phases were right though. With the one wire from each of the wall-warts connected together, measuring across the other two wires should give you something like 36 volts. If it gives you 0 volts, you will need to swap the wires from one of the wall-warts.
*
== CC-BY-NC ==
Readers are permitted to construct these circuits for their own personal use only. Ken Stone retains all rights to his work.
== See also ==
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== References ==
''[https://web.archive.org/web/
== External links ==
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* [http://groups.yahoo.com/group/cgs_synth CGS Synth discussion group], for discussion of locating parts, modifications and corrections etc.
[[Category:CGS
[[Category:Power supplies]]
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