Delayed Car Door Alarm

Opening car’s door is very simple activity, and off course it’s just a daily activity which require no special skill. Almost nothing can go wrong, but forgetting to close the door when we doing or thinking on many tasks is a common thing. This can lead to many consequences, from as simple as air conditioner inefficiency to as dangerous as […]

Read more

Voltage to Frequency Converter Using UJT

The following voltage to frequency converter (V/FC – VCO) circuit consist of a UJT (uni-junction transistor) oscillator in which the timing charge capacitor C2 is linearly depends on the input signal voltage. The voltage across resistor R5 set the charging current, which is accurately controlled by the amplifier. Here is the schematic diagram of the circuit:

Read more

LM139 One Shot Multivibrator/Timer

One shot multivibrator circuit is also known as monostable multivibrator or timer. The function of such circuit is simply produce a pulse strobe with a fixed width, regardless of the pulse width of the triggering input.  Below is the circuit’s schematic diagram of simple one shot multivibrator uses one section of an LM139 comparator. The width of the output pulse […]

Read more

Programmable Capacitance Multiplier with DAC

Capacitance multiplier simulate high capacitance capacitor for analog signal signal processing. By using DAC (Digital-to-Analog Converter), we can simulate variable capacitance with very wide range, which can be used in digitally controlled analog processor (programmable filters for example). The following circuit shows a DAC0830 connected as a capacitance multiplier. This circuit is a DAC controlled amplifier (used capacitance multiplication) to […]

Read more
« 1 2 3 4 5 6 7 8 9 10 11 12 ... 47 »
1 2 3 4 5 47