How to build a simple RF remote control system

Bug Detector Circuit

The circuit, built around a single integrated circuit (Ul, an MC3403P quad op amp), three transistors (Q1-Q3), and a few support components,.receives its input from the antenna (ANT1). The signal is fed through a high-pass filter, formed by CI, C2, and Rl, which eliminates bothersome 60-Hz...

Circuit forms gamma-photon detector

The circuit of Figure 1 includes a PIN photodiode that detects individual photons of gamma radiation. The reverse bias on the photodiode sometimes creates a depletion region. When such a photon strikes this depletion region, a small amount of charge develops. This charge is proportional to the...

Geiger counter

The Geiger tube needs a high voltage supply which consists of Ql and its associated components. The transformer is connected in reverse; the secondary is connected as a Hartley oscillator, and Rl provides base bias. Dl, D2, C4, and C5 comprise a voltage doubler

Negative Ions Detector / Sensor

Ions are defined as electrically charged atoms. Positively charged ions have a deficiency of electrons, and negatively charged ions have a surplus of electrons. An ion can also be classified as an atom or molecule with an electrostatic charge. Another classification of an ion is a charged...

Remote Control using 300 Mhz RF modules

This project will show you how to build a circuit to control things remotely using the the Basic Stamp II and Ming RF modules. I am making a remote engine starter for my truck, but anything you can turn on and of with a Relay could be used in this project. Without any type of anttena the Modules...

Make a truly linear RF-power detector

Modern high-performance transmitters require accurate monitoring of RF power, because most cellular standards depend on strict power- transmission levels to maintain an effective network. Regulation of transmitted-signal strength also lets you build lower cost systems. Figure 1 shows a...

High-bandwidth-peak-detector

The high-speed peak detector uses a highly accurate, fast s/h amplifier controlled by a highspeed comparator. The s/h amplifier holds the peak voltage, until the comparator switches the amp to its sample mode, to capture a new, higher voltage level. The circuit handles all common-wave shapes...

X-Rays with Receiving Tubes

Old TV tubes are used as cold cathode x-ray emitters in a simple apparatus developed by Bob Templeman of Chicago, Illinois. With selected beam power tubes of the type used in the high voltage section of TV receivers, the intensity is adequate to make x-rays photographs of objects using standard...