KC2ZPLs Web Design and Electronic Home

Posted on Feb 5, 2014

Now that I have these power supplies, wouldn`t it be nice to evaluate their performance Traditionally you connect an adjustable load (a `beefy` resistor) to the output and measure both the output voltage and the current in a number of spots. Then it`s easy to plot the ”U/ ”I relationship. Which is nothing more than output resistance at a given p

KC2ZPLs Web Design and Electronic Home
Click here to download the full size of the above Circuit.

oint. You could also connect an oscilloscope to the output and by varying the load, observe the amount of ripple, relative to both the amount of ripple before the stabilizer and the load value. The amount of ripple left over is especially important when working with sensitive receiving circuitry. The additional difficulty posed by high voltage is that all the measurement gear has to be rated accordingly. My tube circuits require anywhere from 150V to 200V so it`s relatively easy to get a pair of multimeters. However, using the oscilloscope is entirely a different matter. Most modern active probes can only be used with relatively low voltages. If you want to go higher, you have to extra purchase a special high-voltage kind which is expensive. I wanted to overcome these limitations by designing a load that is both easy to use and oscilloscope-safe. I didn`t want to go the large adjustable power resistor route and that meant an active high voltage load. Accuracy wasn`t my primary concern. Often times you only need to see how this or that circuit approach compares to the ones before. The following is my attempt at designing the circuit using easy-to-obtain garden-variety components. The circuit here on the left is essentially an adjustable current sink. It`s powered by the DUT itself. A TL431 shunt regulator that forms the current setting 9V stable reference, also powers the Op-Amp. It "steals" about 4. 2 mA of current from the...

Leave Comment

characters left:

New Circuits



Popular Circuits

Temperature controller
220V AC Powered White Led Lamp
555 timer IC audio amplifier circuit schematics
Power failure emergency lights automatically converter circuit diagram
100W HiFi Audio Amplifier Circuit