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Topic: Hacking a touch lamp  (Read 3311 times) previous topic - next topic

Gambituk

Sep 18, 2015, 04:10 pm Last Edit: Sep 18, 2015, 05:55 pm by Gambituk Reason: marked as solved
Hi, i have some touch lamps that i don't use anymore, i would like to make a quick hack to make this web controlled. I know that there are examples to make a normal lamp into a touch activated lamp, but i don't know where to start to signal an existing touch lamp to activate, so i would like to know if someone did something similar with this, i tried to just earth the metal chassis of the lamp to the earth of the power strip, but this doesn't seem to activate it, and i didn't want to  try applying any voltage to it before seeing if there was someone who knew how to do this.

Any thoughts?  :o

I have seen some google posts trying to explain the concept, but it doesn't seem to be clear if it is using the same principle.

Thanks in advance for any thoughts, comments or suggestions

Gambituk

Gambituk

It seems i was a bit too hasty, i retried the grounding with a better cable, and it does activate it this way.  :)

Gambituk

Hmm, i thought it was straightforward after figuring out that grounding would do the trick, but thinking about it, how can i use an arduino to ground the lamp. I guess i would have to use a relay or something similar to connect it to ground?

Zapro

Hmm, i thought it was straightforward after figuring out that grounding would do the trick, but thinking about it, how can i use an arduino to ground the lamp. I guess i would have to use a relay or something similar to connect it to ground?
Yes.

With no more information from you, it's hard to help.

// Per.

Gambituk

Well, i figured out that the touch lamp can be turned on by grounding the chassis, the exterior of the lamp. But i would like to use this fact to make it controlable by an arduino. I know how to send a 5v signal from an arduino, but how can i send a signal which is either ground, or open circuit?

Is there any ideas or suggestions? i would like to repurpose these lamps to make them controllable thru network/internet.

Zapro

If you posted some clear (not too big!) pictures of the electronics, maybe we could help you.

My crystal ball is broken at the moment, so i cannot do anything else for you right now.

// Per.

Gambituk

Well, my question is quite independent of the electronics, in fact, i am trying to avoid going into the electronics too much. I want something that i wont question is electrically safe, so i want to find a solution that doesn't open up the electronics. I'm not asking for an astrological prediction of what the answer might be, i've tried to restate my request quite simply.

Perhaps you've never heard of a touch lamp

It's a lamp that turns on when you touch it with a part of your body (i assume any part will do, but i've only tested with my hands)

Here is a picture.



I realise i've broken some unwritten rule by failing to ignore your sarcastic and condescending remarks, and i'l probably not get any sensible responses now, but that seems to be what is already happening, so i might as well include a picture of an arduino, just incase it helps.




Kisses and hugs

Gambituk

Zapro

#7
Sep 22, 2015, 09:37 pm Last Edit: Sep 22, 2015, 09:37 pm by Zapro
Oh, i though you had it taken apart.

To make the touch circuit work properly, i would try getting a relay-module like this: relay

Connect the relay between the body of the lamp and a ground connection, and see if it works.

// Per.

tristanscomics

Along with a relay, as mentioned above, you have to have tons of resistance. Relays screw with voltage a lot. The lack of resistance can damage an Arduino easily. I sound stupid saying this, but trust me. A lot of people damage their Arduinos when using relay because they just don't have enough resistance. Take the time to find out how powerful of a resistor you need.

My school friend just fried an Arduino Mega today in school because he had a relay but didn't have enough resistance. Stay safe.

Zapro

Along with a relay, as mentioned above, you have to have tons of resistance. Relays screw with voltage a lot. The lack of resistance can damage an Arduino easily. I sound stupid saying this, but trust me. A lot of people damage their Arduinos when using relay because they just don't have enough resistance. Take the time to find out how powerful of a resistor you need.

My school friend just fried an Arduino Mega today in school because he had a relay but didn't have enough resistance. Stay safe.
Seriously man, what have you been smoking? Absolutely nothing of what you wrote above gives any meaning what so ever!

If you insist on "needing extra resistance"  - what ever it means, please back it up with some facts!

The relay board that i linked to has a dedicated transistor and a base resistor for that to drive it - there is absolutely no need for any extra "resistance".

// Per.

CrossRoads

Relays don't need resistance - they just need a proper coil driver. Simple NPN transistor will do. The little 20mA MOSFETs that make up an Arduino output aren't strong enough to support a relay coil. But they can drive a transistor, which can drive a coil.

See attached. The 1N4001 diode dissipates current in the coil when the transistor goes from On to Off.
The LED and resistor is there so you can see when the coil is energized, you can leave that part out.

The Resistor between the Arduino and the NPN base keeps the Arduino from trying to drive too much current out; the base acts like a diode to ground when the Arduino output goes high, having a ~0.7V short on a high output is bad for the Arduino.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

mohit-singh

You can use pnp type transitor and connect its base to arduino pin via 1K resistor which you will use to dim your touch lamp.
Connect emitter side of trnsistor leg to ground and collector side to relay switching pin.
Connect another pin of relay to +12v output from arduino.
So whenever you arduino gives high command to change state of lamp the relay will get on.
Now the relay has another three points NO, NC, and COMMON so whatever you connect to common pin will get out of NC or NO (in your case NO point so connect your ground wire to common and another piece of wire between NO and lamp .
Use relay of 12V 5 amp 230V ratings.

mohit-singh

  Correction  :D  with trnsistor use npn and reverse emitter and collector connection.

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