AC switching

[Druggan]

I have two inductive loads C1 & C2. While C1 is passively connected to an A/C outlet (230 V, 50 Hz), C2 will be switched on demand as per Figures 1 & 2, hereto referred as State 1 and State 2. A suitable signal may be used to trigger the switch gates, say -5 V for State 1 and +5 V for State 2 (to be determined by the designer). The switching frequency may be from zero to say 400 Hz. The maximum operating amperage is 2 A.

 

[KlausST]

Hi,

I have questions ...

First of all: What is your question? I see no problem, no description of a problem.. I don´t know what you expect from us.

Then:
"C" usually is used for capacitors. But here you used it for inductive loads. Is there any reason for this?
In your description there is nothing mentioned about a motor .... but the PDF filename talks about a motor. So is it a motor or not?
Can you modify your inductive loads so that you get one common connectior and one for "in phase" and one for "out of phase" operation?
How much sense does it make to have a 50Hz mains frequency ... but switch the loads with 400Hz? What´s the use of it?
I don´t know what to do with the +/-5V information. I see nothing about this in your draft.
Who / what controls the swtiching?
Are you aware that wrong switching sequence my caue a hard short circuit. Thus you need a clear OFF state before ON again.

You say "to be determined by the designer". Who is the designer if not you?

Klaus

 

[D.A.(Tony)Stewart]

U have 4 active switches which need controlling {time and voltage} switching states for different sequences of L2 coil
0 = off, 1 = on

S1 S2 S3 S4
1 1 0 0 Normal
0 0 1 1 Reversed
0 0 0 0 Off
1 0 0 0 other transition modes.
0 1 0 0 "
0 0 1 0 "
0 0 0 1 "

Several issues are:
1. flyback of high voltage spikes
2. Unknown type of AC motor, (Induction, Reluctance etc)
3. No detailed specs, no questions, no more answers.

 

[BradtheRad]

Your switches are an arrangement known as an H-bridge. You may have some experimental purpose in running two motors in 'sync' at times or else 'out of sync'. Are they located close together? Do you plan to watch what effect their operation has on each other?

It isn't easy to switch house voltage in one direction not to mention back-and-forth using low voltage transistors. Or do you plan to build a special kind of circuit?

 

[betwixt]

I think this is for reversing a single motor Brad. C1 stays across the AC and C2 is in parallel but the winding ends can be swapped. They can be in-phase or anti-phase depending on the switch. It could be done with a double pole change-over switch but I think they are looking for an electronic solution.

Brian

 

[BradtheRad]

In case this is for only one motor (to change its direction)...
I recall many years ago when installing a fan in a warehouse. To run it on house voltage we had a dusty old 1/2 h.p. motor... but it spun in the wrong direction. It didn't matter which way the plug was oriented in the outlet.

I phoned a local electrician to ask if he could reverse-wind the armature. He claimed there should be a small lever on the housing which reverses the direction. After I searched for it and flipped it, the thing spun properly. I don't know what type of motor it was. I don't know what the switch did to the windings.

Your motor's hp is similar. Does it have a similar switch for changing direction?