JPS6013065Y2 - Portable VTR power supply circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power supply circuit for a battery-powered portable VTR.

Currently, there are examples of battery-powered portable VTRs that are designed to save power and protect the battery as described below.

(1) It has a built-in timer, and if the pause state continues for a certain period of time, it will move to stop.

(2) When powered by batteries, do not operate the condensation drying heater even if dew condenses.

(3) Automatically shuts off when the battery output voltage falls below a certain value.

However, this alone is insufficient and further improvements are required in the following points.

If the stopped state continues for a certain period of time, the power will turn off.

Make it impossible to set the timer (program timer) when running on batteries.

An object of the present invention is to provide a power supply device that satisfies all of the above-mentioned power saving measures and that also stops some of its functions when driven by an external power source.

The key point of this invention is that by providing a switch that opens and closes in conjunction with the insertion and non-insertion of the external power input jack, the battery/external power information obtained from this is used to control the various power saving measures mentioned above. It's about doing.

The present invention will be explained below with reference to Examples.

In the figure, when a jack is inserted into the external power input jack 1, the changeover switch 2.3 linked therewith falls to the EXT side, and when pulled out, it is connected to the BATT side.

6 is a diode, and when the external power supply decreases (such as during a power outage or when starting the engine when the car battery is in use), the internal battery 4
This is for backup purposes.

5 is a manual power switch, which is opened by a power off solenoid 9.

Reference numeral 7 denotes a switching regulator, which serves as a power supply unit that supplies power to each part of the VTR.

Reference numeral 10 denotes an over-discharge detection circuit, which sends a signal to an OR circuit 15 when the output potential of the battery 4 becomes below a certain value, and activates an auto-shutoff circuit 20 to stop the operation of the VTR.

Reference numeral 11 denotes a dew condensation detection circuit, which sends a signal to the OR circuit 15 to shut it off when the VTR set becomes dew-condensed, and at the same time provides a signal to the AND circuit 16 as well.

The other input terminal of the AND circuit 16 is E of the changeover switch 3.
It is connected to the XT side, and becomes a high potential to drive the heater circuit 21 only when an external power source is connected.

The heater circuit 21 operates a heater for drying a rotary cylinder (not shown) when condensation occurs.

12 is a timer signal terminal, which becomes a high potential when a timer (program timer) is set.

The other terminal of the AND circuit 17 to which the timer signal terminal 12 is connected is connected to the BATT side terminal of the changeover switch 3, and is at a high potential only when the battery is driven.
7 and drives the warning light circuit 22 to issue a warning to the user.

Reference numeral 13 is a pause signal terminal, which is at a high potential during a pause.

On the other hand, a signal under the same conditions as in the case of the AND circuit 17 is applied to the other input terminal of the AND circuit 18 to which the pause signal terminal 13 is connected.

In other words, only when battery-powered, high potential information representing the pause state passes through the AND circuit 18 and passes through the pause timer circuit 23.
After a certain period of time set by the pause timer circuit 23, a high potential is applied to the auto-shutoff circuit 20 through the OR circuit 15 to shut off the operation of the VTR.

14 is a stop signal terminal, which is at a high potential during stop.

On the other hand, an AND circuit 19 to which the stop signal terminal 14 is connected
A signal with the same conditions as in the case of AND circuits 17 and 18 is applied to the other input terminal of .

That is, only when the battery is driven, the signal passes through the AND circuit 19 and triggers the stop timer circuit 24, and after a certain period of time set by the stop timer circuit 24, the solenoid drive circuit 25 is operated to open the power switch 5.

The present invention is not limited to the illustrated embodiment, and if a microcomputer is used for various operations, these operations can easily be performed using the microcomputer.

According to the present invention, in addition to the conventional power saving and battery protection measures, it also saves power by cutting off the power if the stop state continues for a certain period of time, and disables the setting of the program timer when using the built-in battery. It is possible to implement battery protection measures and extend the effective life of the battery.

[Brief explanation of the drawing]

The figure is a block diagram showing an embodiment of a VTR power supply circuit according to the present invention. 1... External power input jack, 2, 3...
...Selector switch, 4...Internal battery, 10...
...Over discharge detection circuit, 11... Condensation detection circuit, 20... Auto shut-off circuit, 21.
... Heater circuit, 22 ... Warning light circuit, 23 ... Pose timer circuit, 24 ...
・Stop timer circuit.

Claims (1)

[Scope of utility model registration request] In a portable VTR that is driven by selectively using an internal battery and an external power source, a timer is built in and a means is provided to open a power switch and cut off the power supply when the stop state continues for a predetermined period of time or more. , a means for operating a shut-off circuit to shift to a stop state when the pause state continues for a predetermined period of time, and a means for identifying whether the VTR is driven by an external power source or a built-in battery, and only when the VTR is driven by the built-in battery, the above-mentioned 2. 1. A power supply circuit for a portable VTR, comprising means for controlling the operation of two means.