Light Switch

[ronaldrc]

I've never done it but I think it could be done with 2 diodes and a double pole switch.

Both bulbs paralleled and but one bulb has a diode in series so it just runs on DC.

You figure the rest out.

 

[ronaldrc]

I posted this a few minutes ago but for some reason it did get posted.

I said you could do this by using two diodes but one bulb would recieve only DC voltage and the bulbs would be paralleled.

 

[ronaldrc]

What the craps going on my first post wasn't there a while ago?

 

[dbuckley]

I've never done it but I think it could be done with 2 diodes and a double pole switch. Both bulbs paralleled and but one bulb has a diode in series so it just runs on DC.

That allows you to have just bulb A on, or bulbs A and B on, but not just bulb B on.

Four diodes (two at each end) allows all combinations over two core wire, but theres no getting away from the fact that the bulbs only get a half-cycle each, so need to be lower voltage bulbs than the standard 120V items.

 

[dicklaxt]

Would you post up a schematic of a double pole switch,one diode and 2 wires going out to the fixture that has two lights,,,,,,,,,,,


I,m not seeing this at :-?all.

dick

 

[PetrosA]

The first place I worked after school was a really old company that had a storefront and did appliance and lamp repairs as well as electrical. We electricians would do the lamp repairs in our downtime (store staff did it as well) and there was an old guy who came in a few days a week to take care of the appliances. We had an amazing selection of repair parts on hand to fix pretty much anything that came in from candelabra to mogul to fluorescent plus some oddball European sockets as well (a lot of GIs and tourists brought back lamps from their time abroad).

My first thought when hearing about this lamp is that it's probably a "designer" European or Modern style one that would have had a PVC coated three wire going from the switch (3P) to the lamp. If it's a really old lamp, there was probably a cloth coated, twisted three-wire cord going to the lamp which someone didn't have when they went to replace the cord. While I see how it could have been done with a diode, I think that would have been a really rare setup and probably not factory wired.

 

[kwired]

What the craps going on my first post wasn't there a while ago?

If you use the back arrow on your browser you will go back to what you saw before and the newer posts will not appear.

 

[satcom]

Here is the basic idea of floor lamp switches http://www.juddley.com/3_way_lamp_logic.htm

 

[ronaldrc]

Heres a diagram

http://home.comcast.net/~ronaldrc/wsb/Example.html


Kwire , about the my first post I usually do that and refresh my page also,but it wasn't there


Thanks:Ronald

 

[electricguy]

Here is the basic idea of floor lamp switches http://www.juddley.com/3_way_lamp_logic.htm

Thanks Satcom
I been looking for ideas for a science fair for younger kids that I have been asked to do this summer

 

[satcom]

Thanks Satcom
I been looking for ideas for a science fair for younger kids that I have been asked to do this summer

The OP was looking for a 4 position push switch to replace one on a 30's era floor lamp, but the battery and switch example was used for many science fairs over the years.

 

[dicklaxt]

I agree Ronald but that doesn't satisfy the original post as there was no mention of one of the lamps operating with rectified DC.Plis the light without the fiode would be operating at ome half voltage

Satcom your example shows more than 2 wires that was in OP description

dick

 

[ronaldrc]

Hello Dick

He didn't mention anything about brightness or ac or Dc.


Ronald

 

[dicklaxt]

Sorry ,got a phone con before I could finish and edit.Here's the corrected version.:grin:

I agree Ronald but that doesn't satisfy the original post as there was no mention of one of the lamps operating with rectified DC(+) and the other at DC(-).The light with the diode would be operating at one half voltage and the other full voltage, in the two light mode,the lamp without the diode would be at full voltage and when in the one light mode it would be rectified DC.

Satcom your example shows more than 2 wires that was a requirement in OP description

I'm just trying to play by the rules

dick

 

[ronaldrc]

OK

Dick I reckon if you want to look at it that way.

 

[satcom]

Sorry ,got a phone con before I could finish and edit.Here's the corrected version.:grin:



Satcom your example shows more than 2 wires that was a requirement in OP description

.

The OP has a 1930's era floor lamp with a foot switch, the example shows how these lamps were wired, what would often happen, was someone would rewire the older lamps and use 2 wire zip cord to feed from the floor base to the lamp base, most of them had 3 conductors of wires covered with rubber and cotton, which dried up and rotted.

 

[LarryFine]

Would you post up a schematic of a double pole switch,one diode and 2 wires going out to the fixture that has two lights,,,,,,,,,,

If you look at this diagram of Ron's, and alter it by placing a third diode in series with the other switch, but in the opposite polarity, and placing a fourth diode in series with the other bulb, also in the opposite polarity, the two bulbs will switch independently, each from its own switch, as if the other bulb and switch didn't exist.

You'd still use the same two single-pole switches, though.

Heres a diagram

http://home.comcast.net/~ronaldrc/wsb/Example.html

 

[ronaldrc]

Thats right

And you'd think we havn't gained anything. But if you replace the bulbs with motor starter coils you could control two motors with two wires and use a 2 pole switch as a selector switch.

 

[glene77is]

Thats right
And you'd think we havn't gained anything. But if you replace the bulbs with motor starter coils you could control two motors with two wires and use a 2 pole switch as a selector switch.

Ron,

If you drive DC coils from rectified ac,
then you would be applying 60 Hz pulses (120/2),
then you might cause contactor chatter.

If you drive AC coils from rectified ac,
then chatter should be a real problem.

Comments ?

 

[kwired]

Ron,

If you drive DC coils from rectified ac,
then you would be applying 60 Hz pulses (120/2),
then you might cause contactor chatter.

If you drive AC coils from rectified ac,
then chatter should be a real problem.

Comments ?

Use smoothing capacitors to help with chatter?

I have seen this done before -controlling two loads with a single conductor (plus a common)- remember with half wave rectification you also have half the voltage. Harder to find contactors with the right coils.

IIRC the installation I remember seeing had resistors in series with contactor coils to reduce voltage on coil, and they used maybe a 48 VDC coil with 120 VAC source on the whole works.