Design and analysis of a four-bit remote control component capable of remote reset

Four-bit wireless transmitting and receiving components are widely used in various circuits due to their simple peripheral circuits and long remote control distance. However, all four-bit remote control components on the market have a common disadvantage, that is, as long as the receiving circuit is successfully decoded for the first time, one of the outputs will always be high level and cannot be cleared by remote control. This limits the use of the components. For example, if it is used as a four-way remote control switch to control the attraction and release of four relays, it is OK if you want to close three channels at the same time, but it is not OK if you need to close all four channels at the same time. You can only manually disconnect the power supply of the receiving circuit, so that only three channels of the four-way switch can be used.

The solution is to make a small improvement to the original transmitting circuit, so that it has the remote control clearing function. The improved circuit is shown in the figure below. S1-S4 are still the original four-bit buttons A, B, C, and D, which are connected to the four-bit data terminals of the coding IC respectively. When any of the switches is pressed, the coding IC is powered and the data terminal connected to the button is also added with a high level to send a signal outward. When the receiving circuit receives the signal and decodes it through the decoding IC, it also outputs a high-level signal corresponding to the operation button on its four-bit data terminal. When all low levels need to be output, press S5. At this time, the coding IC is powered and works, but the four-bit data terminals are not added with a high level (low level), so after the receiving circuit decodes, its data terminal becomes a low level, and only a jump high level is output at the I/O terminal, thereby achieving the purpose of remote control clearing.