EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: iamdarkyoshi on November 21, 2015, 07:33:52 pm
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I have reverse engineered my touch lamp's controller PCB, BigClive style.
(http://i.imgur.com/HEQIoVq.jpg)
(http://i.imgur.com/qgrKnvN.png)
I have done my best to draw a DaveCAD drawing of the schematic based on the images I had. I used BigClive's trick of taking an image of both sides, and then flipping the image of the backside, layering it on the image of the top, and turning the transparency to about 50%. I love this technique.
The problem with this touch lamp is that it does not like LEDs, or lower wattage bulbs. With LEDs, there is enough leakage to actually dimly light the LED lamp no matter what, and the LED lamp makes the touch lamp much more sensitive, and usually will shut itself off with the slightest bit of electrical noise, and will also tend to turn itself on with electrical noise. If I turn my fan to a different speed, it will always cause the lamp to register a touch. What can I do to make it less sensitive to electrical noise and work better with lower wattage bulbs? The COB is very likely the controller that gives three brightness levels on the bulb and does everything else in terms of sensing. Oh, I should add that I live in the US, so the supply is 120V 60hz.
Thanks everyone!
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try decreasing the antenna impedance and adding series resistance to the switching element
i would try the series resistance first
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try decreasing the antenna impedance and adding series resistance to the switching element
Could you please elaborate?
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you load down the antenna or add some resistance before your bulb/led. this will dissipate energy as heat
i dont know enough about triacs to help you otherwise.
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you load down the antenna or add some resistance before your bulb/led. this will dissipate energy as heat
i dont know enough about triacs to help you otherwise.
The triacs are essentially just AC switches. I am wondering why it is more sensitive the lower the load though.
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they have a leakage current that is significant probobly.
*parallel resistance not series resistance, since it is a current leakage
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they have a leakage current that is significant probobly.
*parallel resistance not series resistance, since it is a current leakage
The 100ohm resistor and 180pf capacitor looks to be what caused the LED to light dimly when the lamp is off. Not sure what that part of the circuit is there for however...
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they have a leakage current that is significant probobly.
*parallel resistance not series resistance, since it is a current leakage
The 100ohm resistor and 180pf capacitor looks to be what caused the LED to light dimly when the lamp is off. Not sure what that part of the circuit is there for however...
It looks like a snubber network but 180pF is too low but the decimal point could be in the wrong place.
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they have a leakage current that is significant probobly.
*parallel resistance not series resistance, since it is a current leakage
The 100ohm resistor and 180pf capacitor looks to be what caused the LED to light dimly when the lamp is off. Not sure what that part of the circuit is there for however...
It looks like a snubber network but 180pF is too low but the decimal point could be in the wrong place.
Just checked and it looks like I messed up the code. it is 100nf.
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I used BigClive's trick of taking an image of both sides, and then flipping the image of the backside, ....
I didn't know anything about this style and did the same, but when someone design from time to time double layer PCBs rather standard way to see at the same time top and bottom PCB from top view-you have to flip bottom image...it is quite obvious.. it is common style :)
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To make an LED bulb work, most people put a shunt resistor (which can be a small incandescent bulb) in parallel. You will have to experiment to find a shunt value that works well, but you could try a 5W bulb.
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Maybe pure testing with Human Body Model could give better results after reading this, since while you have unknown IC on PCB connected to lamp base I guess rather dificult put this thing into circuit simulator? ;)
Fundamentals of Electrostatic Discharge Part Five -- Device Sensitivity and Testing (https://www.esda.org/assets/Uploads/documents/FundamentalsPart5.pdf)
We need HV 100pF capacitor and 1.5k resistor to simulate human body touching this metal base? :popcorn:
Interesting, what physics phenomenon is used in those touch lamps-human "charges" this lamp by touching, or person who touches this lamp is charged? ::)
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Maybe pure testing with Human Body Model could give better results after reading this, since while you have unknown IC on PCB connected to lamp base I guess rather dificult put this thing into circuit simulator? ;)
Fundamentals of Electrostatic Discharge Part Five -- Device Sensitivity and Testing (https://www.esda.org/assets/Uploads/documents/FundamentalsPart5.pdf)
We need HV 100pF capacitor and 1.5k resistor to simulate human body touching this metal base? :popcorn:
Interesting, what physics phenomenon is used in those touch lamps-human "charges" this lamp by touching, or person who touches this lamp is charged? ::)
Mine works by making the base "live" at mains voltage, but at such a tiny current. When you touch it, you have a parasitic ground, so tiny amounts of current flow from you to ground. Its enough to dimly light a string of LED christmas lights if I touch the other side of the string XD