Ultrasonic drilling machine circuit

 Ultrasonic drilling machine is an essential processing machine in the jewelry processing industry. It is mainly used for
drilling and engraving high-hardness materials such as natural gemstones, crystal agate, jade and glass products. The following introduces an ultrasonic drilling machine circuit . For reference by readers engaged in this field.
    (1) Circuit composition The ultrasonic drilling machine circuit consists of a power supply circuit, an ultrasonic oscillator circuit, a drive amplifier circuit and a power output circuit
, as shown in Figure 7-72.
    The power circuit is composed of power switch S, power transformer Tl, dual bridge rectifier circuits AI11 and AB2, ammeter A, resistor F, three-terminal
voltage stabilizing integrated circuit 7815 and filter capacitors cl, c3, C, C6.
    The ultrasonic oscillator circuit consists of resistor island, Ru, RlZ, inductor L, capacitors C7~C9 and transistor VT7. The drive amplifier
circuit is composed of capacitor C4, transistors VT8 and VT9, input transformer 12 and resistors Yong, Ria, R13 and R14.
    The power output circuit consists of the windings W2 and W3 of the input transformer T2, and the power amplifier tubes VT1 and VT6. Resistors S and F, output transformer
T3, capacitor C2 and ultrasonic transducer B are formed. (2) Analysis of working principle: Turn on the power switch S, and after the AC 220V voltage is stepped down by Tl, an AC 20V voltage and an AC 56V voltage will be generated
    on the windings W7 and W8 of Tl respectively .
After the AC 20V voltage is rectified by AB2 and filtered by C3, one channel is added to the collector of \rr9 through the Wl winding
to provide nearly 24V DC voltage for the drive amplifier circuit; the other channel is +15V through the 7815 spike, and works as an ultrasonic oscillator.
power supply.
    After the AC 56V voltage is rectified by AB1 and filtered by G, the ammeter PA provides a DC working voltage of about 60V to the power output circuit.
    The ultrasonic oscillator oscillates after being powered on. The generated ultrasonic oscillation signal is amplified by VT8 and VT9 and coupled to the power output circuit .
After being amplified by VT1-VT6, it drives the transducer through T3 to convert the ultrasonic electrical energy into mechanical vibration energy. , the vibrating head vibrates repeatedly with the combination of grinding powder (usually
emery) and water, grinding the processed parts of the workpiece to form grinding holes or engraving patterns.