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Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
4 channels of 0-10 Volt dimming controlSupports 120 and 220 to 240 Volt, 50/60 Hz applicationsAllows switching of lighting and exhaust fansVisit the Crestron® Lighting Fixture Compatibility page to find out which Crestron lighting devices have been tested and are compatible with third party...
I remember seeing a clever circuit in which the voltage divider for an LM317 was referenced to -1.25 volts, allowing the output to go all the way to zero. The design also had a negative regulator that used the same trick.
There are not a lot of uses for power supplies that can do down to zero, are there?
I agree that it sounds like a bit of an oxymoron, but there are times when it is useful to be able to turn the voltage up from zero or down to zero.
Usually when trying to assess the start-up or shut-down behaviour of some circuit or device.
In fact, in the last year or so I did build a small PSU for injecting 0 to 10v DC test signals into a circuit.
PS, and here it is...
Wow, two years ago.
Doesn't time fly when you are enjoying yourself?
The ZPD's will get hot drawing the same load as output. 3x Si diodes could be better if they were fwd biased unlike reverse as shown.?
My Simulation https://tinyurl.com/2fm3bsbk > 700 mA may overload my model. The negative bias diode ripple is thus added to the output. Crude, but works. (noisy ripple) It might be better to make a bipolar supply then use a regulated Adj current to maintain the 1.25V across ADJ to OUT