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1. Thread: Using transformer at half its rated voltage (both pri and sec)

by johansen
Replies
12
Views
1,047

Yes you can do that, the neutral will carry the...

Yes you can do that, the neutral will carry the sum of both 110 and 230v loads.
2. Thread: Using transformer at half its rated voltage (both pri and sec)

by johansen
Replies
12
Views
1,047

Yes leave the primary disconnected. Put 230v...

Yes leave the primary disconnected. Put 230v across x1 and x4, connect x2 to x3 and you have 110 volts from both x1 and x4 to x2and3.

The transformer only has to supply the difference if you have...
3. Thread: Using transformer at half its rated voltage (both pri and sec)

by johansen
Replies
12
Views
1,047

what is the reason you need to do this? You...

what is the reason you need to do this?

You can use the secondary alone as a 240/120v auto transformer, in which case you can get 3kva worth of 110 volts out of it. (you will also get 480 out of...
4. Thread: Electric heat treating oven

by johansen
Replies
22
Views
1,370

you got close with your drawing but one of the...

you got close with your drawing but one of the elements is not getting power.

in the drawing you have two relays, from the top down they get power on the left side from L1, L2, L3, L3

the input...
5. Thread: Old vs New Motors

by johansen
Replies
30
Views
2,335

Yes and that is the watts output of the shaft. ...

Yes and that is the watts output of the shaft.

Multiply volts x amps x pf x efficiency it should equal the kilowatt rating of the motor.
6. Thread: Electric heat treating oven

by johansen
Replies
22
Views
1,370

Resources - Cress Manufacturing Company Inc....

Resources - Cress Manufacturing Company Inc.

It appears to me that your furnace has solid state relays. They are essentially triacs or scrs back to back. They typically wait until there is 30...
7. Thread: Want to start silver brazing. What are the choices?

by johansen
Replies
14
Views
1,042

Cyanide kid what do you use for stainless brazing...

Cyanide kid what do you use for stainless brazing that doesnt have zinc in it?
8. Thread: Electric heat treating oven

by johansen
Replies
22
Views
1,370

Sounds like a triac or act phase angle control on...

Sounds like a triac or act phase angle control on the oven. Convert it to single phase and run it from the line.

Or replace the pid controllers and use a relay. Heating element life may not be as...
9. Thread: Old vs New Motors

by johansen
Replies
30
Views
2,335

I agree with hermetic in general, yes better...

I agree with hermetic in general, yes better insulation and stator metal allows smaller cheaper and hotter motors.

by johansen
Replies
101
Views
5,147

I would have expected a bit more than that....

I would have expected a bit more than that. typical to supply 15v to the gate to turn on and - something to turn off. i would expect at least 10 volts for turn on, -5 volts to keep it off. or it may...
11. Thread: Building a RPC out of a Dahlander motor

by johansen
Replies
7
Views
756

Bill that would theoretically work, but you would...

Bill that would theoretically work, but you would have to open the motor and bring out all 12 leads for the 6 separate coils.

I just don't think the motor will have any thermal or magnetic budget...

by johansen
Replies
101
Views
5,147

If the output voltage sensing network is damaged...

If the output voltage sensing network is damaged it may think it is delivering full voltage.

Does it have a transformer and then a resistive voltage divider in front of an opamp or an Adc?

by johansen
Replies
101
Views
5,147

Take it, i have 3 phase at work.

Take it, i have 3 phase at work.

by johansen
Replies
101
Views
5,147

anyone interested in this one? Phase Converter...

anyone interested in this one?

Phase Converter - tools - by owner - sale

I'm tempted to buy it as its only \$700 but its an expensive doorstop if I break it poking around.
15. Thread: New shop split unit ductless BTU calculation?

by johansen
Replies
14
Views
1,159

two large window ac units could provide...

two large window ac units could provide (theoretically) 24,000 btu cooling and might only cost you a couple hundred bucks depending on what's on Craigslist in your area.

a minisplit of twice the...
16. Thread: Building a RPC out of a Dahlander motor

by johansen
Replies
7
Views
756

Yes the windings have to be in series for low...

Yes the windings have to be in series for low speed and you will have twice the copper losses for a given current, and 4 times the leakage inductance and the rotor is at half speed.

My guess is on...
17. Thread: HLV-BK half nut missing

by johansen
Replies
5
Views
970

If you can get something close made from delrin,...

If you can get something close made from delrin, you can heat up the leadscrew (don't freak out.. something like 350f is all that is required) and close the half nut on the screw and the threads will...
18. Thread: Another motor wiring mystery

by johansen
Replies
6
Views
609

7 wires could be from a tapped start winding....

7 wires could be from a tapped start winding. Part of it is permanently connected to the run cap, the other part gets the full line voltage through the start switch, but only briefly.
19. Thread: Another motor wiring mystery

by johansen
Replies
6
Views
609

That would be a run capacitor. Its possible the...

That would be a run capacitor. Its possible the start switch shorts out the capacitor for starting, but personally i have not yet found a motor that does that,

7 wires oit of the stator is odd. If...
20. Thread: Another motor wiring mystery

by johansen
Replies
6
Views
609

is that a start capacitor or a run capacitor and...

is that a start capacitor or a run capacitor and what is the uf and voltage rating?
21. Thread: VFD Remote Motor Frequency Meter

by johansen
Replies
9
Views
1,043

you need a 0-10 volt volt meter, 2ma max a...

you need a 0-10 volt volt meter, 2ma max

a number of the cheap lcd digital meters from china such as the one you linked are very hard to read, but not always, you may want a standard analog...
22. Thread: Change gears for a Clausing 4902?

by johansen
Replies
1
Views
304

need a 1:1.5 ratio between spindle and leadscrew....

need a 1:1.5 ratio between spindle and leadscrew. probably not hard to figure out.

or a 3:1 ratio if the leadscrew is 8 tpi. or some other ratio if you have a quick change gear box.

3/8" wire...

by johansen
Replies
17
Views
1,466

List of brazing alloys - Wikipedia...

List of brazing alloys - Wikipedia

many/most of the brazing alloys for stainless steel are on the order of 20% zinc. i forget which alloy i used but it was a rod designed for dissimilar metals, i...
24. Thread: can I reverse this not-labelled-as-reversible single phase motor?

by johansen
Replies
19
Views
1,357

No the yellow and blue wires are at each end of...

No the yellow and blue wires are at each end of the run winding.

One of those other splices should join the midpoint of the run winding with the start winding, which appears to be 2 smaller wires...
25. Thread: can I reverse this not-labelled-as-reversible single phase motor?

by johansen
Replies
19
Views
1,357

This may be one of those motors with the start...

This may be one of those motors with the start winding connected to the midpoint of the run winding. In which case the start cap will be 110 vac rated and you can reverse it by simply swapping the...
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