principle of operation
The radio coding remote control four-stage dimmer switch consists of a radio coding transmitter and a radio decoding receiving controller. The circuit of wireless coding transmitter is shown in figure 1. A 1 is a special transmitter for radio remote control, which is essentially an ultrashort wave radio transmitter module with built-in antenna and no signal modulation. IC 1 is a special encoder for four-level dimming lamps. It uses five-bit binary address codes to encrypt the remote control instructions, that is, each of the five coding ends of A 1 ~ A5 can be set to "1" (open circuit) or "0" (ground), so there are 25=32 non-repetitive codes in * *, which can make the remote control instructions. When SB is pressed, IC 1 outputs the coded serial command from the {17} pin, and applies it to the signal input terminal 1N of A 1 through R2 to modulate the 265MHz RF signal generated inside A 1, and directly emits the coded remote control electromagnetic wave to the surrounding space through the built-in antenna.
①
The circuit of the radio decoding receiving controller is shown in Figure 2, where H is the controlled electric lamp drawn for the convenience of explaining the principle. A2 is a special receiver for radio remote control paired with A 1. It is essentially a radio receiving and demodulating module with built-in antenna, just like a TV tuner. IC2 is a special decoder for four-stage dimming, and it has built-in four-stage dimming control signal generation circuit, which is very convenient to use. Within the effective range, the coded remote control electromagnetic wave emitted by A 1 is received by A2 built-in antenna, demodulated, amplified and shaped by the internal circuit of the module, and then the coded serial instruction signal corresponding to the transmitter is output from the OUT terminal. This signal is directly sent to pin 10 of IC2 for decoding. When the encoding and decoding methods are consistent, pin 10 of IC2 sequentially outputs three-phase trigger pulses corresponding to the number of times that SB is pressed in figure 1, and the conduction angle of bidirectional thyristor VS is controlled by C 1, so that the remote control lamp has three-level dimming (weak, medium and strong) and off functions.
②
In figure 1, VD 1 is the working indicator of the remote controller. In fig. 2, R6, VD2, VD3 and C2 form a simple resistor step-down and voltage-stabilizing circuit, and output 6V d C voltage to power supplies A2 and IC2. R5 obtains the AC synchronization signal of IC2. R3 is the external oscillation resistance of IC2. Increasing or decreasing its resistance can change the brightness difference between the three lamps. R3 value is too large or too small, the dimming is not obvious or the brightness of each block is appropriate. The measured working voltages at both ends of H are about 100V, 160V and 220V respectively.
Component selection
A 1 adopts domestic TWH630 radio remote control transmitter. The module size is 30× 15× 13mm, the working voltage is 12V, the working current is about 4mA after adding modulation signal, and the RF output is 10mW. A2 adopts TW63 1 radio remote control receiver matched with A 1. The module size is 34×26× 13mm, the working voltage is 6V, and the waiting current is 1mA. The remote control distance of the transmitter and receiver is ≤ 100m, and the working frequency is 265MHz. It has the characteristics of miniaturization, long transmission distance, no need for debugging, low power consumption and strong anti-interference ability, and is an ideal receiving and transmitting module for making radio remote control devices.
IC 1 and IC2 adopt a new coding method matched in China, and remotely control the special integrated block for the four-stage dimming lamp. The encoder model is TH980 1, and it is encapsulated with double rows of 18 pins. The model of the decoding dimmer is TH9802, and it adopts double-row 14 pin plastic package. VS adopts 1A, 600V small plastic encapsulated triacs, such as MAC97A6, BCR 1AM-8, etc. VD 1 adopts 3mm red LED, VD2 adopts 1N4007 ordinary silicon rectifier diode, and VD3 adopts 6V and 0.25W ordinary silicon zener diode.
R 1 ~ R5 all adopt RTX- 1/8W carbon film resistor, and R6 adopts RJ- 1W metal film resistor. C 1 uses CT 1 ceramic capacitor, and C2 uses CD 1 1- 10V electrolytic capacitor. 6×6mm miniature four-foot touch switch for SB. G Ordinary electronic lighters use A23- 12V battery (the size is only10X18mm) to reduce the size of the transmitter.
Making and using
Fig. 3 is a schematic diagram of the welding of the printed circuit board of the transmitter. The actual size of the printed circuit board is about 50× 30 mm, and the battery clip is made of phosphor copper skin and directly welded on the circuit board. The whole transmitter is completely packaged in a plastic box of about 54×34× 16mm, and the SB button and VD 1 luminous cap extend from the opening of the box panel. The transmitter is very small and can be worn on the key ring and carried around, which brings a lot of convenience to use.
③
Fig. 4 shows a soldering diagram of the printed circuit board receiving the controller. The actual size of the printed circuit board is about 50× 34 mm. The soldered circuit board can be directly fixed in the insulated base cavity of the controlled ceiling lamp, wall lamp and desk lamp. If you want to control the ordinary chandelier, you can put the movement into the shell shown in Figure 5 and make it into a standard bayonet (or screw) lamp holder type. When manufacturing, the lamp holder directly uses the commercially available bayonet (or screw) lamp holder, and the chuck (or screw) can be taken out from the corresponding waste incandescent bulbs. The shell is made of a plastic oblate box with a size of about 70× 40 mm. This lamp holder type dimmer switch has the characteristics of strong versatility, flexible use and simple installation, and is very suitable for manufacturers to choose when developing products. When in use, just connect the incandescent bulb to be controlled to the lamp holder of the dimmer switch, connect the electric clip at the top of the dimmer switch to the original lamp holder of the bulb, and put the original lamp switch (without disassembly) in the closed position.
④
⑤
As long as the wiring is correct, the device can work normally without any debugging. However, the following points should be noted: (1)IC 1 and the corresponding five address coding terminals A 1 ~ A5 in IC2 must have the same coding, otherwise normal remote control cannot be realized. When coding, just connect the two copper foils corresponding to the circuit board with solder. (2) The installation position of the receiving controller should avoid large metal objects, so as not to affect the receiving effect of A2. (3) This remote control switch can also directly adjust the speed of the electric fan below 100W and turn off the power supply. In order to avoid the induced voltage generated by the fan motor from breaking through VS, a 470V, 100A (peak current) varistor can be connected in parallel at the AC control terminal of VS; When the power of the controlled load is large, the current capacity of the triac increases with each increase of100W. (4) The same number of transmitters can be made at the same time for many people to carry. When it is found that the remote control distance is obviously shortened or the indicator light VD 1 of the transmitter is dimmed during use, the battery of the transmitter should be replaced in time.