The circuit uses one of the four bilateral switches contained in the CD4066, and is a kind of astable multi-vibrator. The main limitations of the circuit are the relatively poor shape of the output signal, and the output signal swing, which is not digitally compatible. These drawbacks are easily overcome, however, by a buffer at the output. When the switch closes, the current in the chain produces a voltage across R3, which raises the switching level at the trigger point by about one volt. Likewise, R1 reduces the voltage applied to R4 to a level below the switch-off voltage. The mark-to-space ratio (duty factor) of the output signal may be varied by using parallel charging resistors, one with a series diode (preferably a germanium type), as shown in the circuit diagram.
In the prototype, the component values shown resulted in an output frequency of 957 Hz with a supply voltage exactly The duty factor was about 0.4 without the parallel RD network .With the network fitted, the output frequency and duty factor were 317 Hz and 0.06 respectively.
The current drain varied between 0.12 mA and 0.39 mA.
Pulse Generator
Pulse generators are electrical test equipment used to generate pulses that are injected into devices under test in order to study the behavior of these devices. Basic pulse generators allow users to control:
- the frequency or pulse repetition rate
- the pulse width
- the pulse high-voltage and pulse low-voltage levels
- a delay for an internal or external trigger
Unlike Function Generators, Pulse Generators are wholly dedicated to generate pulses and for control of pulse related parameters such as pulse width, rise/fall time etc. Various Pulse Generators are differentiated by their pulse repetition rate and the control capability of their pulse width, delay and transition times.
The Pulse Generator block generates square wave pulses at regular intervals. The block’s waveform parameters, Amplitude, Pulse Width, Period, and Phase Delay, determine the shape of the output waveform.
There are many types of pulse Generators few of them are mentioned below:
- high voltage pulse generators.
- 555 pulse generator.
- current pulse generators.
- high current pulse generators.
- mechanical pulse generators.
- stepper pulse generators.
- 1-second pulse generators.
- 4-channel pulse generators.
