Variac. Is there one you like with a digital read out. V and A?
- Thread starter drtool
- Start date
arts
Addicted Member
I don't know of any variacs that come with a digital readout,although some come with an analog meter.
I built one of these into mine (custom case):
https://www.amazon.ca/dp/B014W3D1OC/ref=pe_3034960_233709270_TE_item
I built one of these into mine (custom case):
https://www.amazon.ca/dp/B014W3D1OC/ref=pe_3034960_233709270_TE_item
thorpej
Super Member
I don't know of any variacs that come with a digital readout,although some come with an analog meter.
I built one of these into mine (custom case):
https://www.amazon.ca/dp/B014W3D1OC/ref=pe_3034960_233709270_TE_item
This is exactly what I did, although I bought my meter (this exact one) on AliExpress.
arts
Addicted Member
Gotta find the camera first. Nope,sorry,no wood.For electronic enclosures I'm a metal only kinda guy.
Gotta admit though,the best investment (and let me tell you,nothing these guys make is cheap
) I ever made in my woodworking setup is the 24'' Leigh Super Jig that I use for custom cabinet work. Man,who would have ever thought dovetails and box-joints could be so quick and easy!! The learning curve is steep (not complicated,just lot's of info) but once you've got it mastered,you're running!
Gotta admit though,the best investment (and let me tell you,nothing these guys make is cheap
) I ever made in my woodworking setup is the 24'' Leigh Super Jig that I use for custom cabinet work. Man,who would have ever thought dovetails and box-joints could be so quick and easy!! The learning curve is steep (not complicated,just lot's of info) but once you've got it mastered,you're running!
I use a Kill-O-Watt P4400 upstream of a standard variac to measure line voltage and current draw when bringing up a tube unit. Since the P4400 seems to need at least 90V to work right, I wait until I get the variac up to 90V or so and then switch it to the output side of the variac. That way I can measure exactly what voltage and current the amp under test is seeing.
It's cheap and effective. No dovetails required. I have a Leigh dovetail jig I bought with some other tools. I have yet to try it out. Too busy with tube amps!
It's cheap and effective. No dovetails required. I have a Leigh dovetail jig I bought with some other tools. I have yet to try it out. Too busy with tube amps!
I built my own 'metered' variac using a PowerStat 10B 2.25A autotransformer and a 1 ohm 10W resistor in series with the 'hot' lead going to the outlet. By connecting an AC voltmeter across the resistor, I can measure the current being drawn by the device under test. I'm planning to build a more substantial metered iso-variac using some Simpson AC voltmeters and ammeters I've found on the surplus market, but have yet to put it together. Here is a crude diagram of what it would look like:
And here's the projected schematic:
And here's the projected schematic:
s-petersen
Scott
This is what I use, it starts working at around 65v
Cool meter. I find it a bit odd/unfortunate that it takes that much voltage-wise to start working, as 65V is well past the point where an issue like a shorted transformer or filter caps (in a unit with solid-state rectification) would start to show itself, methinks. Is there a way to feed it 'standby' voltage? Stuff like that is why I prefer good ol' passive analog metering, as it doesn't need any prerequisites, just the sort of input it expects.
-Adam
s-petersen
Scott
I am not sure if the internal power supply is accessible to bypass the variac with a wall wart.
There are digital panel meters on the auction sites with separate power and inputs for measuring and power, but it would be 2 separate meters.
Usually when I am bringing unknown stuff up for the first time, I am measuring the AC value on the rectifier socket, or DC value on the first cap as I am increasing the voltage, long before I am looking at the power meter.
There are digital panel meters on the auction sites with separate power and inputs for measuring and power, but it would be 2 separate meters.
Usually when I am bringing unknown stuff up for the first time, I am measuring the AC value on the rectifier socket, or DC value on the first cap as I am increasing the voltage, long before I am looking at the power meter.
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Here is the power mnitor I made
http://audiokarma.org/forums/index.php?threads/i-built-a-power-monitor-cheap.784432/
http://audiokarma.org/forums/index.php?threads/i-built-a-power-monitor-cheap.784432/
arts
Addicted Member
Very nice DR! If you like miter joints,you might consider one of these lock miter bits,but it requires a router table. Makes a really sexy joint though
(and assembly is much easier!)
Really, that's all you need, as far as I'm concerned. Current works too, but since wattage is voltage times current, it'll still give you a good idea of what's going on. Plus, since most nameplate specs are given in voltage and watts, you've got a target to watch for.
-Adam
Thanks gents. Awhile back I saw one in a You Tube vid., about fixing tube amps. I can see where I need to start putting something together as far as new tools. The varic is on the top of my list. With my moms stroke and taking care of her. I have time like never before to learn new stuff. Hence the DG SE1 plinth. Now I trimmed out one of my HF 22s.
Playing with a DC fan. no noise but extra cooling. Plan to veneer the amp shelf next. Arts, no table...yet, but thanks for the Lock miter bit tip. I really want to try a dove tail joint next. Just sexy. Think I am going to look for a short, used Porter Cable one on the cheep to learn on. On the hunt for my next 6BQ5 Magnavox. Already started to look for some unusual wood for it. Thanks Wayne
Playing with a DC fan. no noise but extra cooling. Plan to veneer the amp shelf next. Arts, no table...yet, but thanks for the Lock miter bit tip. I really want to try a dove tail joint next. Just sexy. Think I am going to look for a short, used Porter Cable one on the cheep to learn on. On the hunt for my next 6BQ5 Magnavox. Already started to look for some unusual wood for it. Thanks Wayne
