Front loading continuous charger

A front loading facility for continuously charging rechargeable batteries in headphones or other device, comprises an enclosure containing a slidable drawer in which rests the device to be charged. The device to be charged has contacts which bear against spring contacts when the drawer is closed, but a spring ejects the drawer upon energizing of a solenoid of actuated latch. A voltage and current regulated power supply continuously charges the batteries through a light emitting diode, which has a secondary function of preventing inadvertent battery discharge.

A front loading continuous charging facility for radio headphones allowing 
for the charging and garaging of headphones or similar devices using 
rechargable batteries. 
FIELD OF THE INVENTION 
The invention lies in the field of continuously charging nickel cadmium 
devices or similar rechargable batteries and the utilization thereof in 
maintaining a fully charged battery state in combination with a front 
loading garaging facility for storage during charging. 
PRIOR ART 
No pertinent prior art is presently known for the combined garaging and 
charging facility presented herewith. However, there is a well known 
feature in cordless telephones which continuously charge the cordless 
handpiece when it is placed on the transmitting module. 
DISCLOSURE 
This invention entitled "Front Loading Continuous Charger" relates to 
certain improvements in rechargable apparatus. 
The objective of continuous charging is to provide a fully charged state 
for rechargable batteries so that the device they are incorporated in can 
be used when needed. 
The object of this invention is to provide a charging facility which 
enables the user to store a radio headphone or other such device using 
rechargable batteries in a pre-formed (dependent on the exterior structure 
of the device) front loading drawer enabling both the charging and storage 
of the device when the drawer is closed. As a result, this invention 
provides an improvement in continuous charging units already available.

According to this invention, there is provided a continuous charging 
facility. This consists of a voltage regulated power supply (7805). The 
regulated DC voltage is passed to a current regulator (TL317) which allows 
a continuous regulated current. It is a well known fact that rechargable 
batteries can be charged continuously at 1/16 their rated capacity without 
damaging the batteries. The current is regulated to 1/16 capacity by R1. 
The regulated current is passed through a light (LED 1) emitting diode 
which becomes illuminated upon contact with the rechargable batteries 
thereby indicating they are under charge. It also acts to stop the 
batteries discharging through the circuit. A second adjustable voltage 
regulator (TL317 A) is also incorporated in the circuit providing an 
adjustable voltage to the + input pin of a comparator. A light emitting 
diode (LED 2) is connected to the output of the comparator. The output of 
the voltage regulator is adjusted so as to supply a trip voltage. As the 
batteries reach a fully charged state, the voltage will rise until a state 
is reached where there is no further increase in voltage. The voltage into 
the +input of the comparator is adjusted so that the trip voltage is at 
such a level that when the charging voltage exceeds this trip setting, the 
light emitting diode becomes illuminated indicating a fully charged state. 
Contact from the charger to the inner sliding drawer is made through the 
springcontacts at the rear of the outer enclosure (S1 and S2). 
According to this invention, there is provided a push button operated 
solenoid (FIG. 1) lock which is spring loaded. The circuit is depicted in 
FIG. 1. A DC power supply provides the voltage to drive the circuit. The 
positive + voltage passes through a diode and then a capacitor which is 
kept charged. The diode (D1) prevents the capacitor (C3) from discharging 
through the circuit. Upon depressing the pushbutton (PB1), transistor (T1) 
is biased into conduction allowing the current to flow to the solenoid 
through the power transistor T1. This current surge causes the plunger of 
the solenoid to be withdrawn. When assembled, the plunger abuts against 
the wedge (W1) in FIG. 2 through the slot A in FIG. 1 of the outer 
enclosure thereby stopping the drawer from being ejected by the spring S3 
located at the rear of the outer enclosure of FIG. 1. The tip of the 
plunger interlocks at the front of the wedge when the drawer is closed. By 
activating the pushbutton, the plunger is withdrawn thereby allowing the 
drawer to spring open. 
According to the invention, there is provided a depression (FIG. 2) in the 
sliding drawer in the shape of the device to be recharged. Within this 
depression are two contacts (H1:H2) which are spring loaded. These 
contacts provide the current for recharging the batteries in the device. 
There are leads from these two contacts which are contacted to two metal 
electrodes located at the rear of the sliding drawer. When the drawer is 
closed these two metal contacts (C1 and C2) make contact with springs S1 
and S2 thereby completing the charging circuit. 
According to the invention, radio headphones or similar devices have two 
external metal electrodes which are attached to the main body of the unit 
(see FIG. 3). These electrodes are depicted in FIG. 3 designated E1 and 
E2. These external electrodes are connected internally to a rechargable 
battery observing the correct polarity so that when the headphones are 
placed in the drawer, they make contact with the spring loaded contacts 
within the depression in the drawer; the contacts being of the same 
polarity. 
According to the invention, a lid (depicted in FIG. 2) which is hinged, is 
placed on top of the headphones once they are placed in the depression 
thereby applying pressure so that a good contact is made. Slots have been 
used to allow the upper and lower edges of the drawer to slide within the 
outer enclosure (slots depicted in FIG. 1). A small roller has been 
incorporated in the upper portion of the outer enclosure to reduce the 
resistance encountered when the drawer is closed by reducing the surface 
area the lid is in contact with the outer enclosure. Foam or springs have 
been used (depicted in FIG. 2-F1 and F2) so that when the drawer is 
ejected, the lid will automatically open due to the applied pressure of F1 
and F2.