Variable Attenuator

This is a variable attenuator circuit. This circuit can be used to reduce the power or amplitude of a signal without appreciably distorting its waveform. Here is the circuit : This circuit uses 2N3685 as a voltage variable resistor with an RDS(on) of 800 Ohm. Using 2N3685 JFET, this circuit will provide excellent electronic gain control because 2N3685 has linear […]

Read more

Switch Mode Regulator Provides -12V Negative Supply from Positive Supply

This is a circuit that can provide -12 V negative supply from positive supply. The output voltage is Vo= -Vin· D/(1-D). The maximum output current is Iout=1·(1-D). Here is the circuit : In this circuit, the ground of U1 is connected to negative output voltage. The input voltage of U1 must be lower than maximum operating input voltage, 36V, because […]

Read more

Buck-Boost (Switch Mode) Regulator Provides 12V from 5-35V Supply

This is positive buck-boost regulator circuit. Using this circuit, we can implement a step-down/up converter with a positive output voltage. This circuit produces an output voltage of 12 V. Here is the circuit : This circuit requieres input voltage between 5 V and 35V. The output voltage is given by Vo=Vin·D/(1-D).  The maximum output current is Iout=1x(1-D). The term (1-D) […]

Read more
1 3 4 5 6 7 30