Jingtong annoying tone mod

Here is the faboulous jt-208 transceiver (136-174 mhz) and it's mod to cancel or reduce that annoying tone coming up at startup. First of all, this beep removing operation is a little bit delicated so is required a good practice with smt component soldering/desoldering. Do not attempt to do it if you have never opened any electronic device. About the opening of the case you can refer to this link. Once you have removed the cover, you have to desolder the 2 ground link that solder togheter the 2 board of the transceiver. Then, look at the other side of the keyboard , you will see near the mic and the speaker hole, a little smt transistor, which is used to amplify the beep signal coming from the pin 12 of the micro. Between that transistor and the mic there are an smt capacitor and a resistor . That capacitor bring the beep signal coming from cpu to the audio stage.To reduce the tone volume you have to substitute that capacitor with one of 5Kpf better if smt package. Be carefull in desoldering and soldering, use the minimal necessary temperature to not broken the link. If you completely remove the capacitor you will never ear any beep even from keyboard pressing. After that, carefully reinsert the 2 connector that link together the two board and re-solder the ground link both side. Re-assemble anything togheter with care, following the instuction given from the same link given above. Now try it, if you think it's still too hi, you can use any other capacitor value between 1k and 10 kpf (Low- Hi volume beep).
Good luck.

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Wood Table lamp design with soft switch

This is one of my favourite table lamp from mine table lamp's collection, is made of wood, plexy and some electronic stuff.

Making this faboulous lamp is possible in just one week.

This lamp gives you a warm light that will make your bedroom really more relaxing due to it's plexyglass-through filtered light

After making the structure I fixed the brushed plexy with some screw from the inside of the frame.

Here is a top view picture of the inside, in the bottom left is the micro switch.

I made different type of it for me and my friend, they love it.

The principle of operation is simply, you have only to push on the roof of the lamp where a microswitch connected to a flip flop power on / off the lamp.

By this way you can light up even in the dark.

Here is also a schematic about using flip flop (cd4013), not the real schematic of the lamp but with some mods everyone can do it himself.

No more searching for switch in the night for me !

and you ?

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Home made SMT Desoldering Station

Working with SMTs (surface mount technology components) is quite difficult without an smt hot air pencil. The prices of smt stations are too high, so I decided to build it by my own, the result is very impressive. Anyone with basics electronics can try to build it, it's made with common materials. An smt desoldering station is made up of :- an heater, that is a powerful solder (min 50watt)- an hot exchanger ( IRON WOOL)- an air pump Surfing the web I find some desoldering homemade stations but all using an aquarium pump. Cause I can't get that pump I decided to substitute it with a mini hair dryer, those used travel, this last have inside a 12 v motor cause the internal resistance coil used to hot the air is also used to reduce the 220 AC to 12 volt, infact inside this little dryer you'll find the coil, the motor and a rectifier bridge. The only thing you need is the motor and the tube chassis so you have to cut the handle. First of all you have to get the hotting element, I used an old 60 watt iron , placing the hotting element inside the end of a long iron tube, (about 20 cm, you can also use the same solder tube if there are no holes ) then surrounded the element with Iron Wool (do not press it inside too much or there will be no air flow) that used for washing pots, this trick make the air go slowly and hotter before get out. Then I used a 1 meter plastic tube ( 0.5 cm ) to transfer the air to the pen. For the tip you can use some hardware shop material, it must be iron, shorter and pointed (never use aluminium or brass they will reduce the out temperature, preferably use copper ). Once you have made the pen you can test it with your breath. Ensure there is no other hole JUST the one from witch you blow your air in, you can also use some hot glue but only for the tail of the solder obviously not for the point !To test: switch on the solder, wait some minutes, lightly blow into the plastic tube, PUT the point at 2 cm from a paper, in 3 seconds the paper must begin to burn or became dark. IF it 's so you are ready to build the air pump, if it's not so, keep on reading here.Perhaps your solder is less than 40 watt powerful or you have stocked to much iron wool, so for your blow it's really hard to pass through , but also there may be too little iron wool and the hot isn't transferred quitely .Experiment with the quantity of iron wool and place the hotting element as near as possible to the tip . Building the air pump isn't so much difficult as it seems, first of all get your mini hair dryer, remove everything except the motor and the final rotor, cut only the handle and the rotor's plastic cover, that from which the air enter ( to get more air flow ), take a plastic 66cl pet bottle (coke, fanta and so on ) cut it making such as a funnel, insert it in the out hole of the dryer use some hot glue to fix it, better if it 's inserted with a little pressure, then take the cap , get a short brass tube of 0.5 cm diameter, make the hole on the cap to fit perfectly the tube, insert the tube, use some hot glue to fix it .Now you can use such metal tube to fit the plastic tube to get air outside . Use a variable power supply 6-12 volt to power the motor dryer and control the air flow, you can use the supply project inside this page next. LOOK at my picture and you will understand anything I mean, by regulating the power supply you regulate the temperature, the more air you pump the more rapidly will be the desoldering. Obviously there is no guaranty that a desoldered component will still function using this kind of station ! Hotting for too much time ( more than 10 secs.) will surely destroy the SMT component. At the end you will have a desoldering smt station for less than 50 $ , with characteristics not really different from those commercials ones.Remember to write to me if you need some extra informations or simply build something !!!!GOOD WORKING !!

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Six channel IR system remote control

This project is a remote control system based on a pic and an universal remote controller for TV, named SIMPLEX.
The IR signal of a specific remote controller is received from an IC receiver(SFH 505 or similar ) and sent to the pic, the inside program decodes the algorithm and switches 6 output ports and the corresponding relays .You can use it to control 6 appliances of your room such as lamp, radio, Hi-Fi , TV , computer and so on .The range is great about 10 meters
Obviously you have to get the right remote controller , I used the above universal TV remote and programmed it with the 2242 code, it corresponds to the code of some Sony and Mitsubishi TV .I took the decoding algorithm from tanzilli.comand picpoint.com (they use a display which gives the numeric resulting code of the key pressed on the simplex) , if you want more search for "Simplex" keyword in these sites.
The code that I've modified to switch six relays also let you test any remote control ir led , because there is a subroutine that beep the active piezo when you press any button . This last function is toggleable by switching on a particular channel (TV channel). Here is the code and the schematic .The final result is that you 'll be able to command all you room appliances without moving a finger. I think it's cool, and you ?

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