Current. I hadn't considered where. I guess either? Thanks, Dave Sent from my iPhone...
80628
rtstofer
Feb 17, 2013 2:55 pm
... I thought we were talking about a 50 mV DC meter. Are you sure you can measure AC with it? The meter internal resistance is what, about 1k Ohms? Were you...
80629
Larry Beaty
beatysmills
Feb 17, 2013 3:39 pm
Both! When you are setting Variac at a low voltage, your output current can exceed Variac limits. Ammeter in output leads. When Variac is at a high voltage,...
80630
andrew.mathison
Feb 17, 2013 4:01 pm
I do believe is that all you need is a double pole changeover switch, generally available from electronics shops and the like. Something like this:- ...
80631
DaveC
davec2468
Feb 17, 2013 4:25 pm
Sent from my iPhone ... Good god, please presume proper interfacing (shunt, rect.)! Dave...
80632
DaveC
davec2468
Feb 17, 2013 4:39 pm
This sounds like a small AC sync motor with dual windings: one for forward, one for reverse. No need to reverse connections (it's AC!); just determine which...
80633
Kerim F
ahumanbeing2000
Feb 17, 2013 4:49 pm
The next two questions are ;) (1) What is the maximum VA (power) rating of your variac? (2) What is the current of the protecting fuse (perhaps breaker) you...
80634
DaveC
davec2468
Feb 17, 2013 4:57 pm
Variac rated 1.4KVA, 10A. What is the max input & output protection I can use? Thanks, Dave Sent from my iPhone...
80635
DaveC
davec2468
Feb 17, 2013 5:01 pm
I would like the meter to read 20A full scale as I plan to replace the Variac with a 20A one in the future. Thanks, Dave Sent from my iPhone...
80636
Larry Beaty
beatysmills
Feb 17, 2013 5:14 pm
Could put a full wave bridge rectifier before the shunt. Of course, the rectifier will have to pass the same current capability of the shunt. This ...
80637
Larry Beaty
beatysmills
Feb 17, 2013 5:24 pm
Fusing: be aware the current capability of a Variac is the little pick off point. You exceed that current capability, it burns up with the wires under it. I...
80638
px_charles
Feb 17, 2013 5:26 pm
I've been to the local electronics store. A DPDT switch works. One can also use a DPDT relay to control a reversible AC motor....
80639
DaveC
davec2468
Feb 17, 2013 5:32 pm
What intelligent circuitry counts 30 turn-ons? Mine has just input terminals... Dave Sent from my iPhone...
80640
Larry Beaty
beatysmills
Feb 17, 2013 6:18 pm
The one between your ears. I had observed once in a while a real light dimming turn on of the Variac I was using. So I set up a large current shunt and turned...
80641
Stefan Trethan
stefan_trethan
Feb 17, 2013 6:39 pm
It has to do with chance. The current depends on the phase (time in ac cycle) when you throw the switch. It's a bit counter-intuitive, but the current is...
80642
Howard Hansen
hrh1818
Feb 17, 2013 6:50 pm
Hello Brenda, You can not use the composite video cables going from the outputs of the DVD and VCR to the TV for recording a TV program on the DVD. Instead ...
80643
Kerim F
ahumanbeing2000
Feb 17, 2013 6:57 pm
Let us assume first that the ammeter will measure the AC input current of the variac. As it wa mentioned 2 or 4 diodes will be needed to rectify the variac...
80644
rtstofer
Feb 17, 2013 8:05 pm
... Doesn't this approach rectify the voltage to DC before it gets to the load? That works great as long as the load will run on DC. It would seem to me that...
80645
Larry Beaty
beatysmills
Feb 17, 2013 8:17 pm
Richard, With a FWB feeding DC only to the shunt, AC still is present on the load. Your FWB is in SERIES with the load. AC in to the in side of the bridge, AC...
80646
Kerim F
ahumanbeing2000
Feb 17, 2013 8:28 pm
... Hi Richard, ... The load of the rectifier (half or full) is just the meter. Outside the box (rectifier and meter) voltages and currents are AC as before....
80647
rtstofer
Feb 17, 2013 8:57 pm
... Yes, wired with the shunt as the load on the rectifier will work fine. Richard...
80648
Andrew Mathison (Alice)
andrew.mathison
Feb 17, 2013 9:00 pm
You must reverse one field relative to the other, exactly as I wrote!!! Reversing both and the motor runs in the same direction as before. Remember - IT'S...
80649
px_charles
Feb 17, 2013 9:03 pm
Thanks Andy. For a layman as myself, just make sure the switch is connected the right way- everything else is easy....
80650
Gooey
gooeytarballs@...
Feb 17, 2013 9:07 pm
That is not correct at all. I manage a dozen or so Yahoo Groups and all have been setup so as to allow attachments to messages. Attachments, however, are...
80651
alienrelics
Feb 17, 2013 9:10 pm
Correct. -I- forbid them. I find it rather arrogant to think your attachment should be sent to every last person in the group. It is also an efficient way to...
80652
alienrelics
Feb 18, 2013 1:39 am
When I said "your attachment", I didn't mean that to pick on you specifically. Steve Greenfield AE7HD...
80653
Paul Read
paulxbe
Feb 18, 2013 9:33 am
Hi Charles, Just get a double pole change over switch and cross over the normally open and normally close contacts on each other pole. Put the supply on the...
80654
normnet2003
Feb 18, 2013 12:56 pm
I recently purchased the following battery: ...
80655
Stefan Trethan
stefan_trethan
Feb 18, 2013 1:37 pm
Maybe there is a protection circuit inside the battery pack which limits the current to something less than 4 amp? I can find no specification for discharge...
