Simple V-MOSFET dimmer circuit

Simple VM【)SFI/T bucket light circuit is the same as 30. It takes
advantage of the extremely high input impedance of the V-MOS field effect transistor and controls
the current flowing through the bulb by adjusting the gate bias of the V-MOS transistor, thereby
changing the brightness of the bulb.
    In the figure, RP and R form a voltage divider.
The resistance of the adjusting potentiometer RP can be changed to adjust
the bias voltage of the gate of the V-MOS tube. Since the V-MOS tube is a voltage control
device, its gate bias The size determines
the voltage between its mattress and source . When R!, the resistance is small, the gate
bias of VF is reduced, the drain and source voltage drops of VF are increased, the voltage across the bulb E is reduced, and the luminous brightness is weakened; when
the resistance of R1r is large When , the VF gate bias increases, the VF drain and source voltage matrix decreases, the voltage at both ends of the bulb increases, and the luminous
brightness increases accordingly. The H RP can adjust the brightness of the bulb E as desired.
    The VF is a DC power supply device, so the circuit uses VDl - VD4 rectifier power supply. One channel supplies
power to the drain and source of the bulb and VF, and the other channel passes through R and RP The voltage divider is used to control the gate bias of VF. When the resistance value RP is adjusted
to the minimum, the potentials of the gate electrode and the gate electrode of VF are equal, VF is cut off, and the light turns off; when RI, the resistance value is adjusted to the maximum
value U {, VF is fully turned on, and the lamp is the brightest. The function of the voltage regulator tube VS is to limit the gate-source
voltage of VF to no more than 10V to protect the safety of VF.
    VF can use BU2358 V-MOS Field effect tube, its Pe. ≥ 50w, withstand voltage ≥ /100V, uses
an aluminum heat sink plate with sufficient area for J and M, and the controllable load F should be an incandescent bulb with a small power of 6()W. .
R.1.1/2W type metal film resistor can be used, other components are subject to special requirements.