T&L Publications

Hi, I just built a digital voltmeter kit with an ICL7107CPL chip. The meter works perfectly, however the circuit is configured so that the meter's inputs are isolated from the chip's 5V supply inputs. I would like to use this voltmeter in an automotive application to monitor the charging system. I p...

The transmitter/receiver is RF. I took apart both units (both of which are battery powered) and the antenna in each unit is a length of wire 8 or 9 inches long and looped in a "U" around the perimeter of the plastic housing. The name on the unit is "Driveway Patrol". I have been ...

Hi. Thanks for your reply. According to the information supplied with the unit, it transmits on a frequency of 434MHZ. The sensor is PIR (passive infrared). The sensor works great. My problem is trying to get the receiver in the house to pick up the 434MHZ signal more than 200 ft. away. This unit is...

I recently purchased a wireless driveway alarm, but the range is too small. It sensor works only up to 200 ft. away from the house. I would like to place the sensor at the end of the driveway about 400 ft. from the house. Is there a way that I can modify the unit to accomplish this?