KR970005338Y1 - 110/220v auto-variable circuit for an adaptor - Google Patents

Abstract

None.

Description

110V / 220V automatic switching circuit for adapter

1 is a circuit diagram of a conventional DC power supply

2 is a conventional automatic switching circuit diagram

3 is an automatic switching circuit diagram of the present invention

* Explanation of symbols for main parts of the drawings

SW ₁ : AC variable switch T ₁ : transformer

D _{1 to} D ₄ : Diode B: Bridge Circuit

C ₁ : Capacitor TR ₁ : Transistor

relay: Relay L: input power line

SCR ₁ : Thyristor G: Gate

R ₁ to R ₄ : resistance

The present invention relates to an automatic switching circuit for the adapter to automatically switch according to the power supply voltage of 220V and 110V.

Various means for supplying a direct current to a variety of electronic products that require a direct current power supply, and in particular, in the case of a product using a battery, adapters have been used as a substitute for a battery.

However, as the AC power is boosted from 110V to 220V, a custom adapter is adopted for this power supply, and the circuit employed in such a case is shown in FIG.

For example, if AC220V is used, set AC variable switch (SW ₁ ) to 220V before connecting to the outlet, and then connect to the outlet, then change the AC voltage at diode (D ₁ ~ D ₄ ) at low voltage in transformer (T ₁ ). Is rectified to obtain the necessary DC power through the capacitor (C ₁ ).

The problem with this configuration is that the AC power is not confirmed and the variable switch is set to 110V and the transformer (T ₁ ) is damaged due to overload, and the required DC power cannot be obtained due to overload. To throw it away.

It is proposed to improve the above disadvantages, smoothing the power supplied to the power transformer, receiving the smoothed voltage and determining the magnitude of the power supply voltage by comparing with the reference voltage, and then switching the output signal to 110V or 220V. The characteristics of this circuit are 110V and 220V, which can be changed from time to time while the relay is in neutral, but first, the cost of using two transformers is high. Secondly, a serious problem may occur due to the occurrence of a fatal error when an abnormality of a circuit element or a defect of a transformer occurs. Third, there is a problem that it is difficult to reduce the size and weight due to the size of a transformer.

The present invention is proposed to solve the above disadvantages, and the power without the transformer is directly supplied to the control circuit through the smoothing circuit, and when directly connected to 220V, the power is directly supplied without unnecessary relay operation. It is possible to provide a compact and lightweight structure without failure.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The overall configuration of the present invention is shown in FIG.

The present invention is a 110V / 220V power supply automatic switching circuit for the adapter having an input tap that can be applied to the AC power supply voltage of 110V or 220V and composed of a smoothing circuit, a control circuit and a switching means, the AC input power is not supplied. In the non-state state, the first switch S / W ₁ inside the relay connected to the transformer T ₁ is always connected to the terminal S / Wc of the input power line L. The pulsation voltage supplied to TP ₁ through circuit (B) is earthed through diode (D ₅ ) and capacitor (C ₁ ) and the direct current is enhanced through resistors (R ₁ ), (R ₂ ) or transistor at TP ₂ . Since a bias voltage is formed to turn on (TR ₁ ), there is almost no resistance even with the resistor (R ₄ ), and the voltage of TP ₃ is close to OV, so the voltage to the gate (G) of the thyristor (SCR ₁ ) is also OV. Close to the thyristor, no operation, 110V bridge When supplying current, the pulsation voltage supplied to TP ₁ through the bridge circuit (B) is earthed through the diode (D ₅ ) and the capacitor (C ₁ ), and the DC current is strengthened through the resistors (R ₁ ) and (R ₂ ). Since the voltage is 2/1 than 220V, the bias voltage is not formed enough to turn on the transistor (TR ₁ ) at TP ₂ through the resistor (R ₃ ), so the voltage dropped through the resistors (R ₃ ) and (R ₄ ) Since it is configured to give a gate signal to the gate (G) of the thyristor (SCR ₁ ), the power supply relay of about 110V is operated.

As shown in the above structural features, the circuit of the present invention is always shorted to 220V, and there is no relay operation when AC220V is supplied, but the relay is operated only when 110V is supplied, so the operation of the relay is extremely stable.

Since the relay is not AC220V, it does not need relay action from neutral to 220V or 110V, so the operation of the relay is reduced to 1/2 than the normal one.

Claims (1)

(Twice) 110V / 220V power supply automatic switching circuit for adapters having an input tap to which an AC power supply voltage of 110V or 220V can be applied, and consisting of a smoothing circuit, a control circuit and a switching means, in a state where no AC input power is supplied. The first switch S / W _{1 in the} relay connected to the transformer T ₁ is always connected to the terminal SWC of the input power line L, and the transistor TR ₁ and the thyristor SCR. ₁ ) is placed between the bridge circuit (B) and the relay (Relay), the diode (D ₅ ), resistors (R ₁ ), (R ₂ ) directly connected to the base axis of the transistor (TR1) and the capacitor (C ₁ ) In parallel, the transistor TR ₁ keeps the relay connected to the 220V switch S / W ₁ when supplying 220V AC. Resistors (R ₃ ) and (R ₄ ) are in series to the gate (G) side of the thyristor (SCR ₁ ) and are paralleled in the middle of the capacitor (C | ₂ ) so that the signal is supplied to the gate (G) only when 110V is supplied. 110V / 220V automatic switching circuit for the adapter, characterized in that the switch of the relay) is configured to switch to 110V (S / W ₂ ).