KR860001705B1 - Constant Frequency Waveform Generation Circuit of High Voltage Heating Equipment - Google Patents

Abstract

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Description

Constant Frequency Waveform Generation Circuit of High Voltage Heating Equipment

1 is a conventional circuit diagram.

2 is a pulse waveform diagram according to a conventional scheme.

3 is a circuit diagram of the present invention.

4 is a pulse waveform diagram according to the present invention.

* Explanation of symbols for main parts of the drawings

OP ₁ : Comparator C ₁ : Capacitor

Q ₁ -Q ₄ : Transistor R ₁ -R ₆ : Resistance

a: Input terminal d: Output terminal

According to the present invention, a pulse waveform corresponding to a high power heating system (High Power Heating System) outputs one pulse for each integer multiple of an input pulse, so that the pulse width is equal to the input pulse, and an integer frequency periodic waveform is generated to accurately synchronize it. It is about a circuit.

Conventionally, as shown in FIG. 1, the input pulses are connected to the n-definition counter 1, and each bit output and input pulses of the counter 1 are outputted through the AND gate 2. Will generate

Therefore, in the case of having a 4 times period, if the input waveform as shown in FIG. 2 (a) is counted by the quaternary counter 1, the bit output of 2 ° is shown in FIG. 2 (b). The waveform appears as a waveform, and the bit output of 2 'appears as the waveform shown in FIG. At this time, when the 2 ° bit output, the 2, bit output, and the input perk are allowed through the AND gate 2, a waveform similar to that of the second (d) is obtained.

However, since this method requires the use of an end gate and a counter, not only the cost of the product rises, but also the power supply voltage cannot be easily supplied, and the interface circuit configuration becomes complicated when using an analog circuit.

In view of the above, the present invention provides an analog circuit using a transistor and a comparator, which not only reduces product cost, but also facilitates interface with the analog circuit, and can also use a relatively high power supply voltage. Invented so that, when described in more detail by the accompanying drawings as follows.

The third diagram, an input terminal (a) comparator his collector to connect the base of the transistor (Q ₁₎ connected to the base of the transistor (Q _2), and the transistor (Q ₂₎ on a collector as shown in ( The output terminal of the OP ₁ ), the output terminals d, the bases of the transistors Q ₃ and Q ₄ are commonly connected, and the resistor Ra connected to the collector of the transistor Q ₄ is connected to a power supply Vcc terminal. The non-inverting terminal (+) of the resistor (R ₁ ), the capacitor (C ₁ ), and the comparator (OP ₁ ) connected to each other is connected, and the collector of the transistor (Q ₃ ) is connected to the inverting terminal (-) thereof. .

In the description of the drawings, reference numerals R ₃ and R ₄ denote resistors.

If described in detail the effects of the present invention configured as described above.

If an input pulse waveform as shown in FIG. 2 (a) is applied to the input terminal of FIG. 9 (a) at the initial time when the power supply (Vcc) is supplied, the capacitor C ₁ is not charged at this time. Since a zero potential appears at the connection point b, a low potential signal appears at the output terminal of the comparator OP ₁ , and the transistors Q ₃ and Q ₄ connected thereto are turned off. As a result, electric charge continues to be charged to the capacitor C ₁ , and the voltage appearing at the connection point c is

(Vc) is

Becomes

In this state, the connection point (b) the potential is inverted terminal of the comparator (OP ₁₎ of (-) when higher than the connection point (c) potential, is termed a high potential to appear the output terminal of the comparator (OP _1), the instantaneous input terminal ( When the input pulse of a) is in the low signal state, the transistor Q ₁ is turned off and the transistor Q ₂ is turned off, so that the collector's potential (output terminal potential of the comparator OP ₁ ) is kept at a low potential state. (C ₁ ) continues to be charged.

In this state, when the input pulse appearing at the input terminal a becomes a high signal state, this causes the transistor Q ₁ to be turned on and the transistor Q ₂ to be turned off, so that the output terminal of the comparator OP ₁ has a power supply Vcc. ) Is applied through a resistor (R ₅ ) to a high potential state.

Therefore, since the transistor Q _{3 to} be connected thereto is turned on, the saturation voltage appears at the junction point c on the collector side thereof, and the transistor Q ₄ is also turned on, so that the charge charged in the capacitor C ₁ is resisted. Discharge is performed through R ₂ and transistor Q ₄ .

If the discharge potential is set to be in a high potential state than the connection point c, the high signal state is maintained at the output terminal of the comparator OP ₁ .

In such a state, when the input pulse becomes a low signal state again, the transistor Q ₁ is turned off and the transistor Q ₂ is turned on so that the output terminal of the comparator OP ₁ becomes a low potential state and is connected to the transistor Q _3. ) And (Q ₄ ) are turned off, respectively, so that the voltage Vc appearing at the connection point c is as described above.

The capacitor C ₁ will start charging again.

That is, a waveform as shown in (b) of FIG. 4 appears and an output waveform having an integer multiple of an input pulse as shown in FIG. 4 (d) is obtained at the output terminal d.

The present invention operated as described above uses an analog circuit composed of a capacitor, a resistor, a comparator, and a transistor to provide an effect of facilitating cost reduction and interface circuit configuration of a product, as well as easily selecting a power supply voltage.

Claims (1)

In the waveform generating circuit integer multiple period for use in the high frequency heating apparatus, an input terminal (a) to connect the base of the transistor (Q ₁₎ connected to its collector to the base of the transistor (Q _2), and the transistor (Q ₂₎ the collector of the output stage and the output terminal of the comparator (OP ₁₎ of (d), transistor (Q _3), and connected in common to the base of (Q _4), a resistance (R ₂₎ connected to the collector of said transistor (Q ₄₎ Is connected to a non-inverting terminal (+) of a resistor (R ₁ ), a capacitor (C ₁ ), and a comparator (OP ₁ ) connected to a power supply (Vcc), and its inverting terminal (-) is connected to the collector of the transistor (Q ₃ ). An integer multiple cycle waveform generator circuit of a high voltage heating apparatus, characterized in that for connection to a.

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