A Look at a Matsunaga SVC-1010 Transformer Automatic Voltage Regulator 

Thanks for the awesome explanation. I have a new electronic version that'll do the switching without and mechanical parts, but now ai understand the theory. I live in Bulgaria in the mountains, so its a light line for our 9 houses connected to it, so summers are pretty much a constant 210V - 223V, but in winter with people running electric heaters it drops to 150V sometimes, which is only good to burn things out with.....like fridge compressors, and my electronic central heating pump dont know what to do with 150V either, so its a vital bit of kit here. Thanks again.

I really like you clip, very clear and siimple.

This is a common design 'flaw' on most servo AVRs. The servo is slower to correct for low input voltages (boosting) because the control board power supply (small transformer in the corner) is getting its power straight from the mains input. In other words, if that transformer isn't getting enough voltage (ie.

thanks for this info. I live in an old house with shady electrical wiring where the lights and other electronics get affected by sudden power loss for less than a second whenever the water pump turns on. I thought an AVR should at least protect sensitive electronics but I guess I have to invest in a UPS.

Thanks for this video. I actually have a servo AVR but it is not relating well.

Thank you for the teardown and explanation. This doesn't look like a good design: 1. What if the motor circuit fails, leaving the brush stuck at a point, maybe even the highest voltage gain of the autotransformer? 2. Unless there is some kind of delayed output, the previous position of the brush could potentially mean anything during startup. 3. If the voltage sags due to some heavy load the wiper would simply add more turns to increase the voltage. What if some lighter load is connected in parallel and the heavy load is disconnected? I might be wrong but I would love to hear how people might have worked out these risks!

Not bad. But you can get some nicer models with a bit more protection and functionality. For about 100$ you can get 2000VA model with a MCB, output relay, adjustable hysteresis, under and over voltage protection (disconnect output when it can't compensate anymore), fan, fan fault detection, auto-reset overload protection, temperature sensor for transformer, auto restart with delay, multiple fault lockout (after 5 overloads in short succession it will permanently trip until manually reset), delayed start (after voltage goes back into range that can be regulated, or when turned first time on, the unit will adjust the servo to proper position and only then turn the output relay on), MCU contrlled, and most of the transformer fully resin poted. Yiyen Electric, SCV III series is really nice. The only deficiency is that they are fixed output voltage (can be probably changed with jumpers inside). But that is usually what you want. They also produce relay based ones. Still if you get this one for 10-20$ it is good enough for playing with it.

Só de pensar que algum tempo atrás eu tive essa mesma ideia, mas é uma pena porque eu não coloquei em prática para desenvolver o projeto de um estabilizador automático. Eu fico feliz de ver que este funciona muito bem por mais que não tenha sido eu quem o projetou.

How can we build a constant voltage stabilizer by diy ?

Thanks for this awesome explanation

Very nicely done

somebody told me that there are SVR's just like the SVC-1010 and electronic ones called AVR's, which is the best for electronic appliances? I mean fast enough to catch up and down voltages.

There’s no isolation between input and output is there. Not that there’s a 240 volt input.

What a interesting bit of kit and I love the analog nature of this device. Do you know what it was designed to supply?

My brother, I have a Japanese regulator, Stack 500. Unfortunately, when I connect it to the electricity, the amp turns on, but the coil in your left hand is broken and smoke comes out of it, and the coal is not damaged and does not work...Is there any hope of fixing it and how is the way with thanks?

interesting, thanks !

Really informative video. I recently got a servo type avr and it does provide consistent output. I did notice though that within the 2 weeks that I've owned it, there were around 3 instances wherein the servo made a loud sound (similar to the sound in your video when the motor moves when there is an abrupt voltage change). I understand that the servo motor moves slightly quite often, but the ones I heard, though very rarely, make it seem that there is a sudden change in voltage. Didn't notice any fluctuation of electricity though. Is this normal?

so are voltage regulators quick enough for home theater components or would you just recommend a good line conditoner instead (without voltage regulation)?

👍👍👍

This seems slow compared to the relay based AVR, but again the relay based AVRs are choppy because it can only correct the voltage in "ranges" and it also creates sparks when a relay snaps into position.

Have sell in VN ?

very interesting video. I want to learn more about this. can you give me a source where I could learn about the circuit on this board?

Is the transformer step up or step down

Do these produce a true sine waveform? My gut says they should but I been wrong before :-)