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 Post subject: I just built a simple gadget .Guess what the 5 parts are.
PostPosted: Aug Wed 07, 2019 9:11 am 
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Joined: Sep Thu 23, 2010 6:37 am
Posts: 11711
Location: Powell River BC Canada
Part 1 line cord.

Part 2 duplex receptacle .

Part 3, 4, 5 ???




If two incand bulbs are plugged into the outlets. (both bulbs same, i.e 60 watts.

One will light, the other will remain dark.

If the dark lamp is removed the lighted one will go out.

Other than an idiot puzzle, the thing has an important use.

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VE7ASO VE7ZSO
Amateur Radio Literacy Club. May we help you read better.
Steve Dow
ve7aso@rac.ca


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 Post subject: Re: I just built a simple gadget .Guess what the 5 parts ar
PostPosted: Aug Wed 07, 2019 9:56 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 4101
It could work as a Triac tester, with parts being Triac, resistor, and a triac socket.

The dark bulb and resistor are on the control pin of the triac, and the lit bulb is controlled by the triac. Plug in the bulb to be lit and it's dark. Plug in the dark bulb and it stays dark while the other bulb lights. Unplug the dark bulb and the light goes out.

Ok, I confess, it's been a while since I've messed with triacs and I can't remember if they stay on until shorted. It that case the third part would have to be a switch or maybe a shorting diode.

Is this on the right track?


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 Post subject: Re: I just built a simple gadget .Guess what the 5 parts ar
PostPosted: Aug Thu 08, 2019 1:27 am 
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Joined: Aug Thu 06, 2015 2:20 am
Posts: 175
Not the answer that you are looking for because it's only one component.

How about a transformer (turns ratio to be determined) with one 60 Watt bulb in series with the primary and another 60 Watt bulb across the secondary.

With the secondary loaded, the bulb in the primary will light but the secondary will not because of the lower voltage on the primary because of the voltage drop on the primary from the first bulb.

When the secondary bulb is removed, the bulb on the primary will likely extinguish because of the high reactance of the now unloaded primary.


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 Post subject: Re: I just built a simple gadget .Guess what the 5 parts ar
PostPosted: Aug Thu 08, 2019 2:45 am 
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Joined: Sep Thu 23, 2010 6:37 am
Posts: 11711
Location: Powell River BC Canada
The three parts are a 28 volt relay, a 117 to 28 volt transformer and a bridge
rectifier. The relay is special, it has to start a pump drawing 8 amps to run
and it takes 25 inrush amps to start.


The pump plugs into one side of the duplex receptacle , and will start when the relay closes.

The other side of the duplex receptacle furnishes line voltage in series with the transformer
primary.

The objective is to use any home appliance with a mechanical timer, that uses a motor
or a heat element to start the pump and have it run for what ever time is wanted, then stop.

At line voltage the transformer draws about 8 watts. In series with the device, there is about
8 volts drop.

Many ways to do this , however , none easy and likely be found in junk box.

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de
VE7ASO VE7ZSO
Amateur Radio Literacy Club. May we help you read better.
Steve Dow
ve7aso@rac.ca


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 Post subject: Re: I just built a simple gadget .Guess what the 5 parts ar
PostPosted: Sep Tue 24, 2019 8:43 pm 
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Joined: Mar Tue 03, 2009 11:12 pm
Posts: 1534
Location: Hutchinson KS
This sort of reminds me of the accessory Sears sold to plug your shop vac and table saw in and whenever the saw was started the current drawn would activate a relay inside the accessory to automatically turn on the shop vac to suck up the sawdust.


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 Post subject: Re: I just built a simple gadget .Guess what the 5 parts ar
PostPosted: Sep Wed 25, 2019 4:36 am 
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Joined: Sep Thu 23, 2010 6:37 am
Posts: 11711
Location: Powell River BC Canada
Yes I have several "smart" plug bars that use one master outlet that is always on,
and will turn on the others when it senses a load. But these are dainty things
that would no last starting a water pump motor. The bars are made for turning
on home entertainment components.

_________________
de
VE7ASO VE7ZSO
Amateur Radio Literacy Club. May we help you read better.
Steve Dow
ve7aso@rac.ca


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 Post subject: Re: I just built a simple gadget .Guess what the 5 parts ar
PostPosted: Sep Wed 25, 2019 4:03 pm 
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Joined: Mar Tue 03, 2009 11:12 pm
Posts: 1534
Location: Hutchinson KS
I'm sure the ones that are used to start a shop vac will handle a water pump. Most shop vacs draw 10 amps or so.


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 Post subject: Re: I just built a simple gadget .Guess what the 5 parts ar
PostPosted: Sep Wed 25, 2019 5:49 pm 
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Joined: Sep Thu 23, 2010 6:37 am
Posts: 11711
Location: Powell River BC Canada
The pump I used this on draws 8 amps, and is a 0.33 HP induction motor. Running this pump
over the years resulted in destruction of a few plug bars because of continuous overheating.

My next improvement will be to add a capacitor box right at the well.

The power factor at the motor is about 0.6. I can shed amps downstream this way
and things will not overheat.

The major problem with imported cordage is the skimping on copper. Industrial/contractor
class products are expensive, hard to find, and even now made abroad.

Electrical power is just as snarky as it was 100 years ago, and no amount of euphemistic
product claptrap changes that.

_________________
de
VE7ASO VE7ZSO
Amateur Radio Literacy Club. May we help you read better.
Steve Dow
ve7aso@rac.ca


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