It's alive, thank goodness!

Thank you all for the kind comments and happy new year! One note to add to avoid confusion: Instead of thinking in terms of parallel/series of winding, we can note that the input consists of an auto-transformer followed by a regular two-coil transformer. The auto-transformer provides variable ratio while the regular transformer provides the isolation. Please note that the auto-transformer itself provides no isolation as it only has a single coil where all three terminals are electrically connected.

I like the human interface of this device, everything is so nicely and so clearly labeled.

Great to have you back again...very Happy New Year!

So happy to have you back

These are great isolation transformers; bought mine years ago. "Excellent presentation" you won't be disappointed with this gem.

Whenever I need an isolated mains socket, I use one of those cheap car invertors that make 120V AC out of 12V DC. I get 12V for it from my lab power supply. The resulting AC is not the best in shape, but fits most of the purposes such as fixing the power supply of some home consumer electronics.

So good to see you back, Happy new year!!!

A very good new year and good to have you back again with new videos.

wow. finally updated. could you do a tour of your new home lab ?

Yay, The SignalPath Video! What a great beginning of 2017 :) Wish you all the best, and more great vid's ;).

Nice to have you back. Really looking forward to all the nice videos that will be coming.

YAY!!1 HAPPY TO HAVE YOU BACK, SHARIAR!

Thanks Sir , I'm happy to see you back with new project again..Wish you a happy prosperous start on the new year

Happy new Year!! nice to see you back :)

Glad to see you back :) I love your repair videos.

Nice to see you back ☺

Great to see you again....

I'm looking forward to seeing more tests using the Sencore unit. As a longtime subscriber I am pleased to become a patreon supporter of your channel!

Another great video, Thanks Shahriar!

Glad to see you back,

Welcome back and happy new year

Happy new year. Welcome back ;-)

Very good information on all your videos.

welcome back and New Year!

hey. welcome back:) we missed u.

Have a great new year

Finally , I had gone through withdrawal from being addicted to your channel ;) Now I will be hooked again , doggy dew ;)

Sencore had a parallel company called BAPCO. The equipment was in the biomedical market. A 20amp version of the PR570 was produced. I found 2 for my audio amplifier shop!

Well come back! Thumbs up.....PEACE

Remarkably similar in design to a variable isolation supply I am building. I put a load resistor that I can switch in series with the output to protect against a short in the DUT. I used commercially made voltmeter and ammeters for monitoring, and a bar graph indicator to show voltage across the load resistor. The variable voltage is via a variac which is a variable auto transformer, same as in your unit.

Finaly a new video

Happy New year Shahryar, finally updated. please also post a video about high speed PCB simulation software tutorial.

welcome back.

Oi vey! I thought you were dead... after waiting like 6 million years! I like your videos, senpai ~

welcome back

Very interesting, they have the variac before the 1:1 isolation transformer. I guess that works and I'm sure they did it like that for a reason.. I am planning to make something sim. but with rectification for DC output as well as the variable AC. Also plan on doing some very stable 3.3, 5, and 12v outputs, also thought about figuring out way to do bipolar tracking DC outputs.. Anyway in my head I was planning to start with isolation transformer followed by Variac

If I designed that for the 110-120 volt market, I would have made the main transformer into a 1:2 turns ratio, so that one could output 220-240 +the extra that the variable transformer gives. Maybe split the 1:2 ratio into two taps, so one could select 1:1 or 1:2, so we could use thicker wire for the 1:1 to get better current carrying capability if needed.

It's a shame there doesn't appear to be a 240VAC version of this unit.

do you use deoxit fluid on pots and crusty conections? it works very well.

cat still being a cat as per usual, things seem good.

This is quite a surprise. I thought you had vanished into a distant sunset never to return.

I have a question I'd like to throw out. I have a Heatkit IP-5220, same basic design, simpler metering. The topology is the same, Variac first from the mains, then the isolation transformer, to the power outlets on the front of the unit. There is also a direct non-isolated utility outlet on the front. The main fuse for the unit is 7 amps. The variac is rated for 3 amps. Output metering/fusing is switchable for 1 or 3 amps. Just want to give as much info as possible about the unit. What I would like to do is reconfigure it so that the iso trans comes first, the output of that goes to both the variac and one of the power outlets to provide direct line voltage isolation,. The out put of the variac to the other power outlet for variable voltage. The question is, will I run into trouble swapping the order of the variac and iso trans? What considerations go into putting them in a particular order?

Happy new year! Does it matter whether you put the variable transformer on the primary or the secondary side of the isolation transformer?

omg. Yay!

👍👍

Hey mate, Siglent Spec Analyzer review coming?

is it just me or was the repair part totally missing? either way thankful for a new video

I wish I can effort one

11:23 Kitty

What makes the variac and main transformer to be in parallel? I would call it serial.

What is the amperage of the output? Variac looks small..

What do you mean "short videos will not be charged to patreon"?

Yes, but what happens when you try to charge your iPhone with 300v?

Hi. I wonder if there are other options than this PR570 available on the market or used? I am primarly interested in 230V input and 0V-270V output. 1000VA would be enough. Something that has nice display with all measurements shows at the same time, less knobs, and active output regulation, so the output is stable even if the input varies, and output relay cutoff if the regulation can't be performed. The PR570 is really dated, looks like a design from 80s probably. And it doesn't have active regulation. So you probably should stick input it into inverter or automatic voltage regulator. The PR570 also looks like a really low power, maybe 400W? That can be done this days easily using solid state inverter instead with very little cooling.

Can you please share the schematic if the devices you showing in the video ?

Hello Shariar, is there any replacement for this device (something similar like that)? This one is too hard to find anywhere. Thank You

Are you sure about the fact that the iPhone charger is a buck converter? Considering that it is easy to access its terminals, some kind of isolation is definitely needed for people's safety. I'm voting for a flyback but I'm not sure. Can you confirm this? Thanks

woo hoo

Your cat is defective. They're supposed to stop right in front of the camera.

"it's functional, but it has a small problem" and that works how exactly?

You are still speaking far too quickly - SLOW DOWN please!