JPS6026559Y2 - inverter circuit - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an inverter circuit that converts direct current to alternating current.

A conventional single-stone inverter circuit that converts DC input into AC or DC output has a closed loop consisting of a DC input power source 1, a transformer 2, and a switching transistor 3, as shown in FIG. Transistor 3 with pulse
and 4, and output conversion is performed by the switching operation of the transistors 3 and 4.

However, when the circuit shown in FIG. 2 is used in a high frequency range, the turn-off time becomes longer due to the accumulation effect of the transistors 3 and 4. Even if the width of the output pulse of the pulse generator 5 is narrowed, the transistor There is a drawback that the output pulse widths of Nos. 3 and 4 are not narrow.

The purpose of this invention is to completely solve the drawbacks of the conventional single-stone inverter circuit as described above, and to provide an inverter circuit that can shorten the turn-off time of transistors even when used in a high frequency range. It is something to do.

This invention will be explained in detail below with reference to embodiments shown in the accompanying drawings.

In Figure 1, El is a DC input power supply, T is a transformer,
TIP is the primary winding of the transformer T1, Tl51 is the first
The next winding, Tl52 is the second secondary winding, Ql, Q2 is a switching transistor, Q3 is a reverse bias transistor, C2 is a drive signal generator for transistor Q3, Dl is a bias diode, D2 is a rectifier diode, R1 and R
2 is a bias resistor, C1 is a smoothing capacitor, and C4 is an output voltage.

In this circuit, an output voltage E3 obtained by rectifying and smoothing an alternating current voltage induced in a second secondary winding Tl52 by a diode D2 and a capacitor C1 after being transformed by a transformer T1 is used as a reverse bias power source for transistors Q1 and Q2. There it is,
When the transistors Q1 and Q2 are turned on by the drive currents of the transistors Q1 and Q2 supplied from the DC input power supply F1 via the bias resistor R2, when the transistor q is turned on by the drive signal IF, the transistor Q2 is turned on. The base potential becomes a reverse potential by C3, and the transistor Q
At the same time, bias resistance B1, diode D□ and transistor Q are applied to transistors Q and Q2 due to the influence of C3.
The operation is such that a reverse bias resistance is applied through the .

Therefore, the delay in the off time of transistors Q1 and Q2 due to the accumulation effect is compensated for.

That is, when the transistor Q3 is turned on, its collector potential becomes -C3 port since the collector-emitter voltage becomes approximately zero port.

At this time, the charges accumulated in the capacitor C4 flow through the closed loop of the capacitor C1, the bias resistor R1, the bias diode D□, the transistor Q3, and the capacitor C□, and are discharged.

If this current is IB, the bias resistor R1 has R□・
A voltage at IB is generated, providing a reverse potential between the base and emitter of transistor Q1.

Further, a forward voltage drop occurs in the bias diode D1, giving a reverse potential between the base and emitter of the transistor Q2, and both transistors Q and Q2 are turned off.

At this time, the drive current I. is DC input power supply E1 - bias resistor B2 - transistor Q3 - second secondary winding Tl52 -
Flows through the closed loop of diode D2-DC input power source E1,
Transistor Q1. It does not flow into Q2.

Then, when the transistor is also turned off, the drive current flows through the bias resistor R2 to the base of the transistor Q2, and this transistor is turned on.

As a result, transistor Q1 is also turned on, and this operation is repeated thereafter.

Therefore, even when used in a high frequency region, the transistor Q
, and the width of the output pulse of Q2 can be narrowed, so that the output voltage E to be taken out from the first secondary winding Tl51
, can be controlled from low voltage to high voltage.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of an inverter circuit according to this invention, and FIG. 2 is a circuit diagram showing a conventional example. El...DC input power supply, T1...Transformer, TIP...Primary winding, Tl51...
・First secondary winding, Tl52... Second secondary winding, Ql... Switching transistor, Q2
......Drive transistor, Q3...Reverse bias transistor, D...Bias diode, D2...Rectifier diode, R1, R2
...Bias resistor, C1...Smoothing capacitor, R2...Drive signal generator for transistors Q□ and Q2.

Claims (1)

[Scope of utility model registration request] A transformer having a DC power supply, a primary winding connected to the DC power supply, a first secondary winding and a second secondary winding including a smoothing circuit, and a transformer connected to the secondary winding. a Darlington-connected switching transistor that operates with the input of the DC power supply and has a reverse bias resistance, and a reverse bias transistor whose collector is connected to the base of the switching transistor and whose emitter is connected to the smoothing circuit. , a drive signal generator connected between the base and emitter of the reverse bias transistor, and a diode connected between the collector of the reverse bias transistor and the Darlington-connected base-emitter connection point of the switching transistor. When the reverse bias transistor conducts, the output voltage of the second secondary winding smoothed by the smoothing circuit is transmitted to the Darlington-connected emitter of the switching transistor via the reverse bias resistor. An inverter circuit path characterized in that an applied voltage is applied to the inverter circuit.