This blog will keep to a simple theme of my tinkering with electronic and computer related toys, gadgets, projects and the like. I do hope from time to time there is something for someone to find when they are exploring these things for themselves. From an early age, I was always attracted to electronic gadgets an I continue to enjoy myself with my hobby. Unfortunately with a busy life, time becomes short an I can not indulge myself like in the past.
This experiment uses a variable resistor to change the frequency of the sounds; in addition, when the switch is turned on, the capacitance of the oscillator is increased because the capacitors (.005 and .047 microfarad) are in parallel, and this lowers the oscillator frequency.
This experiment is basically the same as experiment #33, except for the placement of the 10 microfarad capacitor and a disc capacitor. The variable resistor is used as before to change the sound of the gun.
In this experiment, a variable resistor (0 to 50000 ohms) is used to control the oscillator's frequency rate. This give the effect of electronic rain (not real world rain) pouring down at very low resistance and drizzling at very high resistance.
This experiment is using the same basic oscillator circuit introduced in experiment #28. But, the oscillator's resistance is electronically varying. The 1,000,000 ohm resistor and 10 microfarad capacitor slowly increase the base voltage (base current) on the transistor (NPN-Left). As the base current slowly increases the collector current (NPN-left) also increases slowly. The transistor (NPN-left) is now limiting the current just as a resistor does. When the switch is turned off, a similar effect occurs as the 10 microfarad capacitor slowly discharges. Note: I short the capacitor at the end to silents the siren.
This experiment uses the same oscillator circuit as used in the previous experiments. Here, a switch is used to form a telegraph. Telegraph's where widely used in the last half the the 19th century before telephone systems. Telegraph's have only two states on and off. A code called Morse Code was developed by Samuel F. B. Morse of dots and dashes (long or short transmission burst) to send message in the form of electrical current along wires for communication.
This experiment is an oscillator circuit with a trip wire. The alarm is turned on by disconnecting a wire and turned off by connecting the wire (trip wire). The trip wire creates a "short circuit" across the transistor base, so no current flows into the base of the transistor and it stays off. When the "trip wire" is disconnected, the short is removed, and the circuit works sounding an alarm.
In this experiment, a speaker, a transformer and an oscillator circuit (made up of a transistor and varying resistors and capacitors) is used to create sound. A speaker converts electrical energy into sound (mechanical vibrations). In order for the speaker to work, energy from an AC electrical signal is needed. This is achieved with the transformer (converts high-voltage/low-current to low-voltage/high-current) and an oscillator circuit made up of one transistor and varying capacitors and resistors.
