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The wireless doorbell presented then broke down when installed exterior transmitter, the ringer switch, when two of its SMD resistors broke to try to fix the wireless doorbell transmitter on the flat head screw.
The receiver, which is ringing as such, has no problem, the wireless switch is who suffers the damage caused by trying to fix the same place or outside on the flat head of a metal screw.
Lousy Ring transmitter design by the manufacturer regardless of the detail and the user who was the one who installed the switch wireless doorbell, were the causes which combined to cause the damage could be even greater for being fueled circuit with 12 volt battery.
These wireless doorbells are very friendly and helpful when almost laptops, and I say almost because the receiver and the tone generator element is connected to the AC outlet in your home or office so you can leave without warning claddagh door knocker beep call to-door in case of power outages.
A good practice would be to place the receiver ringer claddagh door knocker to one of the outlets of UPS or backup computer in use to always have the sound signal emitted by the doorbell calls for visits to the front door. It is an electronic circuit low consumption hardly bear to the UPS computer.
In the figure below the back doorbell transmitter (Tx) and cover with the hole in it should claddagh door knocker hang this to set the switch on the wall or door shown. As shown the screw head will fall just above the oscillator circuit comprises two transistors and resistors type SMD surface mounting also.
In this case, try hanging the transmitter switch wireless doorbell to fix, contact was made with two resistors smd busting and leaving inoperative switch having no power to the collectors of the transistors of the oscillator circuit.
To determine the value of each SMD circuit resistance was necessary claddagh door knocker to perform a calculation for transistors claddagh door knocker in common emitter configuration according to the approximate characteristics of transistors nomenclature J6 marked on its surface.
The calculation gave 210 kilohms for R4 and R5 about 95 kilohms for. They managed to get the SMD resistors extracted from discarded electronic circuit boards but saved for reuse components claddagh door knocker in good condition; one smd KQ resistor 200 and another 100k. They were soldered to the circuit but with some difficulty to be somewhat larger than the original and do it with a pencil type soldering iron 40 watts.
Welding work in electronic circuits where there SMD components must be done with miniature thermal welding or soldering SMD clamp for the job with quality. Only remove the original electronic printed circuit SMD components is a problem when you do not have the tools necessary to work in circuits with SMD components.
After placed and soldered resistors smd instead of the circuit, each corresponding to the collectors of the SMD transistors, with prior proven its good standing with the meter in the scale of resistance for each measure, the battery is placed and He flipped claddagh door knocker the switch on the transmitter. Complete success, the buzzer is activated and sounds at about 35 meters away from the switch.
A few days after this repair work done, very simple in appearance but complex on the other hand, I could see the design value of resistance to fall into my hands, in an appliance store products; 220 kilohms for 100k for R4 and R5, very close these values to the calculation performed.
The solution for mounting the circuit without damaging the lid was fixed by glue to the outer surface of the switch claddagh door knocker structure but enclosed in a metal trunk leaving visible only to actuate the button. The latter to prevent "accidental" release of the element by "entertaining" people.
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