JPH01237868A - Triac control signal output circuit - Google Patents

Abstract

PURPOSE:To make an external waveform shaping circuit unnecessary and to output a TRIAC control signal not depending on software by incorporating a TRIAC signal output circuit in a microcomputer. CONSTITUTION:An effective waveform is detected out of signals inputted from an AC board 2 by a waveform detection circuit 3. When the effective waveform is detected, a timer 4 starts count down from a value set in advance, and simultaneously, an FF5 is set. Only the output of the FF5 corresponding to the board selected by a register 6 is outputted to a TRIAC control signal output board 8 via an AND circuit 7. When the timer 4 overflows, the FF5 is reset, and the TRIAC output board 8 is turned off. A register 1 is used for the selection of the effective waveform.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a triac control signal output circuit built into a microcomputer.

[Conventional technology]

Conventionally, by inputting commercial frequency (50Hz/60Hz),
There is no microcomputer with a built-in circuit that can detect valid waveforms and control multiple triacs. The conventional technology will be explained below. Figure 2-1 is a circuit diagram of a waveform shaping circuit used in a conventional triac control signal output circuit, Figure 2-2 is a waveform diagram showing a commercial frequency and a triac control signal, FIG. 3 shows a flowchart of software that controls the process from detecting a valid waveform from the shaped waveforms to outputting the triac control signal.

In FIG. 2-2, (9) is the commercial frequency, αO is the waveform after waveform shaping, and (11) is the triac control signal.

Next, the software of the microcomputer@ will be explained. First, a valid waveform is detected by software from the waveform after waveform shaping (IQ) that has been shaped by the waveform shaping circuit shown in Fig. 2-1. When a valid waveform is detected, it is determined whether or not to output a tryout. Checks multiple flags to select, and if the flag to output is set, triac output is performed.Next, the program waits for a period of time during the triac output period, and after the required time has elapsed, the triac output is turned off.
FF 0 [Problems to be Solved by the Invention] Since the conventional triac output control is performed as described above, a waveform shaping circuit must be provided outside the microcomputer. In addition, it was necessary to use software to handle a series of operations from detecting the effective waveform to outputting the triac control signal, which placed a heavy burden on the software. Additionally, since it is handled by software, there are some issues that need to be resolved, such as some variation in the timing of inputting the effective waveform and the triac output time.

This invention was made to solve the above-mentioned problems, and it is possible to omit a waveform shaping circuit outside the microcomputer, reduce the burden on software, and reduce errors in control signal output timing, etc. The aim is to make it as small as possible.

[Failure to solve the problem]

The triac control signal output circuit according to the present invention has a waveform detection circuit etc. inside a microcomputer and is capable of controlling a plurality of triacs. Detects a valid waveform, turns the output to ○N, and starts the timer. When the above-mentioned timer overflows, the output is turned off.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram of a triac control signal output circuit built into a microcomputer. In the figure, (1
) is the register A that determines the effective waveform, ! 21 is an AC port for inputting external signals (commercial frequency), (3)
is the register A (1) among the signals coming from the AC port (2).
), (4) is a timer that changes the pulse width of the triac signal, (5) is a flip-flop whose output is inverted by the overflow signal of timer (4), and (6) is a Register B, (7
) is an AND circuit that outputs only the port selected by register B (6), and (8) is a triac control signal output port.

Next, the operation will be explained. First, a valid waveform is detected by the waveform detection circuit (3) from among the signals input from the AC port (2). Next, register A (11) selects a valid waveform. When a valid waveform is detected, the timer (4)
starts counting down from a preset value. At the same time, flip-flop (5) is set.

The output of the flip-flop (5) is outputted only to the port selected by the register B (6) via the AND circuit (7) to the triac control signal output port (8).0 Next, when the timer (4) overflows, the The lip-flop (5) is reset and the triac control signal output port (8) is turned off.

〔Effect of the invention〕

As described above, according to the present invention, since the triac/signal output circuit is built into the microcomputer, there is no need to attach an external waveform shaping circuit, and triac control signals can be output without depending on software. can.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a triac control signal output circuit built into a microcomputer, Figure 2 is a circuit diagram of a waveform shaping circuit in conventional triac control technology, and a waveform diagram showing commercial frequencies and triac control signals. 3
The figure is a flowchart for outputting triac control signals by software. In the figure, (1) is register A, +2) is AC port, (3) is waveform detection circuit, (4) is timer, C5) is flip-flop, (6) is register B, (7) is A
ND circuit, (8) is triac control signal output port,
(2) is a microcomputer. In addition, in the drawings, the same reference numerals indicate the same or similar parts.

Claims (1)

[Claims] A triac control signal output circuit built into a microcomputer, equipped with an effective waveform detection circuit that can select an effective waveform using a register, and multiple triac control signal output ports that can control multiple triacs.