P. G. Wilson wrote: > Is it true that rectifiers generate a constant minimum AC voltage (rms) > that causes variable ripple depending on actual or overall voltage? In > explanation, is ripple defined by the minimum AC voltage over the rated > output voltage only? > Could the group enlighten me on the subject of minimizing ripple and how > it affects plating? There's been much discussion about copper plating, > and I would appreciate some information on this topic. > Chemist, IUP, CU > P.G. Wilson > [log in to unmask] I am reluctantly answering this post since I have no plating experience. Several things have been stated in this question that I think need clearification. Yes, rectifiers that transform AC to DC have ripple. In a power supply, commonly called an unregulated power supply, the ripple is determined by the filter cap and any load resistance as seen from the DC output of the power supply. A simple unregulated power supply could be just a transformer, full bridge rectifier, output filter cap, and the resistive load. In this setup, the ripple is ONLY determined by the combination of the load and the cap. Now I don't know how technical you want to get, but here's something to think on: Let's call the min/max value of just the output ripple the peak-to-peak ripple = Vripplw(p/p). This is NOT measured with hand held meter. This is measured with an oscilliscope. It assumes the min value is zero volts - the datum if you will. The max value is measured up from the min by however many volts it is. It is a "RELATIVE" measurement to start getting technical. Now, let's do an "ABSOLUTE" measurement on the output. We want to measure the peak output voltage from REAL zero volts also with an O-scope. We will call this measurement = Vpeak. We'll also call the output cap = Cout, and the output resistor (load) = Rout. We also have to know the frequency of rectification, i.e. fulwave is 120 Hz, half wave is 60Hz, etc... We'll call this f. Theoretically, Vripple(p/p) = Vpeak/[R*C*f] For full wave rectification (120 Hz), Vripple120(p/p) = Vpeak/[R*C*f] ******************************************************* ------------------------------------------------------- The comments and opinions stated herein are mine alone, and do not reflect those of my employer. ------------------------------------------------------- ******************************************************* *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************