Wireless Lock Tone


Posted on Feb 6, 2014

When I got the car I was relieved that it didn`t `chirp` or blare the horn every time I locked or unlocked the doors. Let`s face it, there are times when we don`t want our comings and goings announced in such a tactless manner. Still, I found that in the daytime, when walking away from the car, or after forgetting until I`m some distance away, I c


Wireless Lock Tone
Click here to download the full size of the above Circuit.

ould not tell if the car was locking or unlocking. I found on the crossfireforum. org website an idea to install a device that gives out a gentle tone that can be heard from a short distance and does not announce the locking or unlocking like the opening of a Broadway musical. The circuit I designed has a single-pole, double throw push-button switch. In one position, the buzzer in the circuit quietly beeps. In the other position, the lamp in the circuit flashes. The reason for the lamp is to provide a diagnostic function to aid in troubleshooting if problems develop. I mainly put the switch in to provide an easy way to disable the beeping sound if for some reason I didn`t want it to operate. I removed the relay and wrapped the wires around the 85 terminal (positive) and 86 terminal (negative). After shaping the wires, I removed them and put some solder on them to help them keep their shape. Then I replaced the wires on their respective terminals, and reinstalled the relay in its socket. Here is a view of the wiring coming from the relay in the upper right corner of the picture. Black is ground and white is positive. Note the thicker red wire coming off the fuse bank. This is the switched positive lead that goes to the auxiliary fuse box I assembled and installed in support of my stereo install. I took this opportunity to route the red stereo wire and the leads for the buzzer through a rubber port provided for this purpose....




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Security Lock with keypad and LCD (PIC16F84A)
Thermally Operated Direction Detector
Circuit diagram 500mW FM PLL transmitter 88-108MHz using LMX3206 and PIC16F870
Amp RC
General-Purpose Alarm
Stabilized Adjustable Power Supply 0-15V/5A
The 203 Theremin
JFET-Bipolar Cascode
A typical electronic volume control circuit
Low noise preamplifier circuit diagram of the speech



Top