¿ªÔÆÌåÓýHi, I was also going to mention that you might be better served by a UPS. The right type would include Surge Suppression capability, and performs a direct conversion of AC to DC to AC. This includes most Pure Sinewave Output UPS devices. ? Make sure that when it is running on Battery Power that it is not a Stepped Sine Waveform (many are that way). The Stepped Waveform UPS devices can have problems with EnergyStar Compliant PFC (Power Factor Corrected), Power Supplies that may be used in your modern design bench equipment. ? Your Tube Tester is older and would obviously not have PFC. ? It will also regulate your voltage to correct voltage. ? Ross ? From: [email protected] <[email protected]> On Behalf Of si_emi_01
Sent: Tuesday, February 21, 2023 8:44 AM To: [email protected] Subject: Re: [Test Equipment Design & Construction] A bit of Odd ware for the bench ? HI, ? Yup, the Impedance of those old SOLA Power Conditioners could cause a lot of dissipation and they made good foot warmers during the winter. ? To put it a little into perspective, the MIL-STD-461 LISNs that were being discussed earlier in another thread have an 8uF Capacitor and 5 Ohm R-C from each Line Input to Chassis Ground. In a MIL-STD-704 115V, 400Hz, 3 Phase Wye (Phase A, B, C and Neutral), Power Setup Chassis Ground was Common. ? At 400Hz Power each LISN pulled 2.10A of current dissipating 241.5 Watts. You had to have four LISNs on the table (one for each Phase plus Neutral). They were warm without any load connected. ? We had a dedicated High-Power Motor-Generator for the Lab to maintain isolation from other labs. The Motor Generator circuit was able to handle the LISNs, their high Power Factor plus any load we ever threw at it. It was powered by 3 Phase 480V 60Hz ¨C so it was expensive to run. It was powered off when not in use. ? At 120V 60Hz, the LISNs only pulled 0.36A which was only 42.76 Watts and were cool to the touch. ? Ross ? From: [email protected] <[email protected]> On Behalf Of Eric ? I have a new to me Sola constant voltage transformer. I am curious as this is a VERY vintage model it has an output at 115 Vac. I am hoping to use this to soften the power line in for some of my tube testers so that i can take some of the stress off the line adjust pots in the testers as they are becoming unobtainable. However being new to this gear I am not sure what is "normal operation" and should I change the cap. It has an extremely large non polar 16uF cap at 660 Volts. This is a bathtub oil filled capacitor. Also the input characteristics are HORRINDUS under no load it is burning about 84 Watts of power. But it is happily supplying 118.5Vac to a dmm and nothing else. It also has an appauling power factor of about .224 |
