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110V Timer Switch

R

Roy

Jan 1, 1970
0
Hi. Im a hobbyist and I got a timer switch which is rated 110V. I need
to use it in a 220V power source. I need to convert it to 220V without
using a transformer. Can I use a resistor in series to the timer? If
yes, what would be the resistor rating I should use. Any help will be
greatly appreciated.
 
N

N. Thornton

Jan 1, 1970
0
Hi. Im a hobbyist and I got a timer switch which is rated 110V. I need
to use it in a 220V power source. I need to convert it to 220V without
using a transformer. Can I use a resistor in series to the timer? If
yes, what would be the resistor rating I should use. Any help will be
greatly appreciated.

Hi. Is it a mechanical timer or an electronic one? Mech ones can have
a [flameproof] resistor in series, but tronics arent nearly so easy.

Regards, NT
 
P

petrus bitbyter

Jan 1, 1970
0
Roy said:
Hi. Im a hobbyist and I got a timer switch which is rated 110V. I need
to use it in a 220V power source. I need to convert it to 220V without
using a transformer. Can I use a resistor in series to the timer? If
yes, what would be the resistor rating I should use. Any help will be
greatly appreciated.

Well Roy,

There are a lot of timers and even much more switches. What kind of timer
are you talking about? What type of switch? Does the switch use the same
mains connections the timer does? What do you want to switch with it?

petrus
 
W

Walter Harley

Jan 1, 1970
0
Roy said:
Hi. Im a hobbyist and I got a timer switch which is rated 110V. I need
to use it in a 220V power source. I need to convert it to 220V without
using a transformer.

How come you can't use a transformer? Size, weight, cost?? The answer (and
the answer to petrus' questions) will help guide the solution.
 
R

Roy

Jan 1, 1970
0
petrus bitbyter said:
Well Roy,

There are a lot of timers and even much more switches. What kind of timer
are you talking about? What type of switch? Does the switch use the same
mains connections the timer does? What do you want to switch with it?

petrus

Petrus, the switch uses the same mains connections as the timer does.
Its a mechanical timer type of switch capable of 12 on/offs per day.
Inside the switch I can see gears and sort of a motor rated 120V 3W
60HZ connected to the mains. If I use a transformer to bring down the
power source to 110V, then the output voltage becomes 110V too. What I
need is to make the timer run on 220V. Need it to control just one
40watt flourescent lamp for my shop. Any ideas?
 
K

Ken Taylor

Jan 1, 1970
0
Roy said:
Petrus, the switch uses the same mains connections as the timer does.
Its a mechanical timer type of switch capable of 12 on/offs per day.
Inside the switch I can see gears and sort of a motor rated 120V 3W
60HZ connected to the mains. If I use a transformer to bring down the
power source to 110V, then the output voltage becomes 110V too. What I
need is to make the timer run on 220V. Need it to control just one
40watt flourescent lamp for my shop. Any ideas?

To be honest, it sounds like a less-than-$20 timer from a
hardware/electrical store is going to be a heck of a lot easier, and
probably safer than fooling around with this thing's wiring. Or if that's
too much money, hunt around - I'm sure they'll be on special somewhere local
to you for less than$10.

Ken
 
G

Gary Tait

Jan 1, 1970
0
Hi. Im a hobbyist and I got a timer switch which is rated 110V. I need
to use it in a 220V power source. I need to convert it to 220V without
using a transformer. Can I use a resistor in series to the timer? If
yes, what would be the resistor rating I should use. Any help will be
greatly appreciated.

Keep in mind, outside of poweing the timer, the switch contacts must
be rated for 250V or greater, and you must have two poles (one for
each line of the 220V supply). An easy way out would be to have a
contactor control the 220V line, and use the timer, un-modified, to
control the coil in the contactor.
 
N

N. Thornton

Jan 1, 1970
0
Petrus, the switch uses the same mains connections as the timer does.
Its a mechanical timer type of switch capable of 12 on/offs per day.
Inside the switch I can see gears and sort of a motor rated 120V 3W
60HZ connected to the mains. If I use a transformer to bring down the
power source to 110V, then the output voltage becomes 110V too. What I
need is to make the timer run on 220V. Need it to control just one
40watt flourescent lamp for my shop. Any ideas?


Well thats easy, you need a suitable value R in series with the motor
that will drop 110v and dissipate 3w. Then your V_motor will be about
right. I assume you're still using the same mains frequency? If not,
forget it.

But I would say one thing here. A 3w dissipating R is a potential
firerisk. It will all need to be fully firesafe, which does imply some
level of knowledge /skill. Also any certifications on it will beome
invalid, this could possibly be a prob if used commerically... etc. In
other words, I cant suggest doing it, even tho its not the bigest of
risks, there is at least some potential for things to go wrong.
Obadvice: dont so it.


Regards, NT
 
B

Baphomet

Jan 1, 1970
0
Ken Taylor said:
To be honest, it sounds like a less-than-$20 timer from a
hardware/electrical store is going to be a heck of a lot easier, and
probably safer than fooling around with this thing's wiring. Or if that's
too much money, hunt around - I'm sure they'll be on special somewhere local
to you for less than$10.

Ken

Agreed! There's no nobility in reinventing the wheel.
 
G

GPG

Jan 1, 1970
0
If timer has small synch motor put a res in series. Measure current at
110 to get value, wattage
 
T

Taco R. de Vries

Jan 1, 1970
0
If timer has small synch motor put a res in series. Measure current at
110 to get value, wattage

The question is, would it spin slower at 50 iso 60 Hertz??
 
P

petrus bitbyter

Jan 1, 1970
0
Roy said:
Petrus, the switch uses the same mains connections as the timer does.
Its a mechanical timer type of switch capable of 12 on/offs per day.
Inside the switch I can see gears and sort of a motor rated 120V 3W
60HZ connected to the mains. If I use a transformer to bring down the
power source to 110V, then the output voltage becomes 110V too. What I
need is to make the timer run on 220V. Need it to control just one
40watt flourescent lamp for my shop. Any ideas?

Roy,

You can connect a resistor of 4kOhm, >3W between the motor and one of the
mains has been connected to. Four 4kOhm, 1W in series will do. Keep in mind
that this resistors become hot. So you have to be carefull where to place
them. It must be impossible to touch this resistors from outside the
enclosure but it also may not melt the enclosure or heat the other content
to much.

As for the switch, the current required by a 40W lamp will not harm it. But
the switch should have been rated for 220V. If it's only rated for 120V it
nevertheless may cause no problem, but you cannot be sure.

BTW. You timer is rated for 60Hz. It may run slower or not at all when you
use it on a 50Hz mains. It also may use more then 3W (so produce more heat)
under this circumstances.

I conclude that you can experiment with it and may be you get it to work.
But be carefull, 220V can be lethal. If you want to have a reliable timer,
you'd better buy a new one.

petrus.
 
R

Roy

Jan 1, 1970
0
Thank you everyone for sharing your ideas. Petrus, thank you. I will
definitely try that and let you know the result.
 
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