Various Power Supply Circuits
This page is somewhat incomplete. But does provide a couple of Schematics of power supply circuits that I have been using for quite a number of years for one purpose or another.
The DC to power DC supplies offer an excellent power supply of 24 to 30VDC either Positive or Negative outputs from a single + 13.8 VDC (typical Ham shack PS). The simplicity and cost is far better than purchasing Transformers and associated components to construct your typical Linear 24VDC power supply.
A couple of the images show the power supply’s that I am using except the heat sink is a simple piece of flat Aluminum 1/4″ thick & 3″ in length secured to the chassis wall of what ever I may be using it in. Not those shown.
I use the Positive version to power, or drive the many 24VDC relays I have in operation. The Negative PS is an excellent PS for the very common Microwave Bricks that use either a -19, or -20VDC input. Although this has NOT been a problem, you might consider placing an RMI shielding cover over the power supply module. I have not done this and have noticed no birdies or interference of any kind.
Another application is Portable, and /or, Mobile use where something higher than 13 or 14VDC is required in either one, or both polarities.
A MUST DO: Make certain all relays have a reverse biased diode & 0.1uF Cap. across the coil to prevent back EMF from entering the regulators. A practice I usually make is to also place a forward biased diode in series with the line out from the regulators, perhaps a bit of over kill. But piece of mind is worth it.
Another note: remember to provide electrical isolation between active device and heat sink using adequate thermal compound.
Below are Images of Various Power Supplies:
i) DC to DC Positive
Schematic of Positive version.
ii) DC to DC8
Rather crude; but very functional circuit for + version.
iii) DC to DC7
Another view of + version. NO heat sink installed.
iv) DC to DC2
v) DC to DC Neg
Schematic of Negative version
vi) DC to DC
Another crude; but functional version of the Neg. PS
vi) DC to DC3
Side view of Neg. power supply showing un-common heat sink. NOT recommended for service installation.
vii) 1071 case
Case description and pin out function of LT-1071, & LT-1070.
5 Amp & 2.5 Amp version respectively
Below is a Schematic for a Tetrode Screen & Grid Supply that has served ve1alq and many people very well for a number of years. The protection circuit while relatively simple provides excellent protection form over currents, etc
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