Boiler electronic cleaner

The boiler electronic descaler introduced in this example is to change the physical properties of minerals in water by high-frequency electric field treatment of water, thereby achieving the purpose of descaling and anti-scaling.
The circuit is buried in the boiler. The electronic descaler circuit consists of a power supply circuit, a 2OOkHz rectangular wave oscillator, a drive amplifier circuit, and an output indication circuit, as shown in Figure 8-153.

The power circuit is composed of a power transformer T2, a rectifier diode VD4-VD9, a filter capacitor C5, C6, and the like.
The 2OOkHz rectangular wave oscillator circuit consists of a time base integrated circuit ICl and related peripheral components.
The driving amplifying circuit is composed of a high-power electronic switch integrated circuit lC2, an output transformer Tl, and a capacitive load CL.
The output indication circuit is composed of an ammeter PA, rectifier diodes VD2, VD3, and current mutual inductance coils L1, L2, and the like.
After the power switch S is turned on, the AC 220V voltage is rectified by T2 and VD4-VD9 is rectified, and +100 voltage and +l2V voltage are respectively generated on C5 and C6, wherein +100V voltage is applied to the primary winding of the output transformer T1. , +12V voltage is supplied to ICl and IC2.
After the 200 kHz rectangular wave oscillator is energized, a 150-220 kHz rectangular wave signal is output from the 3 pin of IC1. After the rectangular wave signal is amplified by lC2, the capacitive load CL is driven by the output transformer T2 to generate a high-frequency electric field to enter the water of the boiler. Process it.
After the electronic cleaner is in operation, there will be a current indication in the ammeter PA.
Adjusting the resistance of the potentiometers RPl and RP2 can change the operating frequency of the rectangular wave oscillator.
Component selection and installation
Rl, R2 and R4 select 1/4W carbon membrane resistor for use; R3 selects lW carbon membrane resistor for use.
RPl and RP2 use small solid potentiometers or sealed variable resistors.
Cl-C3 selects monolithic capacitors; C4 and C6 select aluminum electrolytic capacitors with a withstand voltage up to 6V; C5 selects aluminum electrolytic capacitors with a withstand voltage of 160V.
VDl-VD3 selects 1N41482 type silicon switch diode for use; VD4 and VD5 select lN5406 type silicon rectifier diode for use; VD6-VD9 selects 1N4007 type silicon rectifier diode for use.
ICl selects NE555 type time base integrated circuit; lC2 selects TWH8751 or TWH8778 type high power electronic switch integrated circuit.
The capacitive load CL is composed of a copper mesh, an insulating tube (porcelain tube or glass tube), and an inlet pipe of the boiler. First install the copper mesh in the insulating tube, and install the insulating tube in the inlet pipe of the boiler. The capacitive load CL is connected to the electronic cleaner circuit by a coaxial cable: one end of the coaxial cable core is connected to the non-ground end of the secondary side of the output transformer T1, and the other end of the core wire is connected to the copper mesh; the coaxial cable shielding One end of the wire is connected to the outer wall of the water pipe, and the other end of the shield wire is connected to the ground end of the secondary side of the T1. A waterproof rubber seal is applied to the outlet of the insulating tube to ensure that no water is introduced into the copper mesh.