GB2091531A - Automatically operating fish feeding mechanism - Google Patents

Abstract

An automatically-operated fish feeder comprises a food storage hopper (10) having an outlet (12) controlled by an electrical motor- operated dispensing device (14), the motor being powered by a battery (18) under the control of a timer (20). An array of photocells (16) is mounted on the lid of the hopper (10) to provide a trickle charging current for the battery (18) and also to provide an indication of the ambient light conditions so as to prevent operation of the motor during the hours of darkness. <IMAGE>

Description

SPECIFICATION Automatically operating fish feeding mechanism This invention relates to automatically operating fish feeding mechanism, especially but not necessarily exclusively for use on outdoor ponds and offshore fish cages. The majority of automatic fish feeding mechanisms in use at present are powered by electric motors. Some of these have AC motors and are intended for use indoors where mains electricity is available. Other types use DC motors which can be battery powered. The battery powered feeder is best suited to use on outdoor ponds and offshore cages.

The main disadvantage with the battery powered type is that the batteries require recharging or replacement at regular intervals and these operations tend to be time consuming and expensive and, in certain cases, e.g. remote cage sites, bad weather etc. may prevent recharging or replacement being carried out.

The object of the present invention is to provide an automatically operating fish feeding mechanism which avoids the above mentioned drawbacks.

According to the invention we provide a feeding mechanism comprising a food storage and dispensing unit operable to dispense food under the control of a battery powered electric actuator and electrical circuit means controlling operation of the electric actuator to determine the duration of the dispensing cycles and the intervals between such cycles, characterised in that photosensitive means is provided for converting solar energy into electrical energy to effect recharging of the battery and said electrical circuit means comprises solid state timing circuitry to minimise current drain on the battery.

According to an advantageous aspect of the invention, there is provided disabling means responsive to said photosensitive means for overriding the timing means so as to prevent operation of the electric actuator (which may be a DC motor) when the ambient light falls below a predetermined level, e.g. to restrict feeding to daylight periods.

In a preferred embodiment of the invention, the photosensitive means comprises an array of solar cells which are conveniently mounted on an exposed surface of the storage unit; for example, the storage unit may be in the form of a hopper having a lid and the solar cells may be provided on the lid. Conveniently, the timing circuitry and the battery are accommodated within the hopper.

In order to promote further understanding of the invention, one example will now be described with reference to the accompanying drawings in which: Figure 1 is a diagrammatic cross-sectional view of a feeding mechanism in accordance with the invention; and Figure 2 is a circuit diagram of the electrical circuitry associated with the feeding mechanism.

Referring now to the drawings, as shown in Figure 1 the feeder comprises a hopper 10 having an outlet 12 controlled by dispensing device 14 which is operable by an electric motor (not shown) to regulate supply of food from the hopper via the outlet 12. The electric motor is controlled by the circuitry shown in Figure 2 which essentially comprises an array 1 6 of so-called solar cells for converting solar energy into electrical energy, a battery 1 8 and a timing circuit 20 which may be positioned on the hopper as shown in Figure 1.

Thus, the battery and timer 18, 20 may be accommodated internally of the hopper while the solar cells 1 6 may be located externally on, for example, a removable lid 22 for closing the open top of the hopper.

Referring now to Figure 2, the output terminals 24,26 of the circuit are, in use, connected to the electric motor for controlling the device 14.

Electrical power is supplied to the terminals 24, 26 from the battery 18 via lead 28 and lead 30, the latter being connected to terminal 26 through the emitter-collector paths of transistors Ol and Q2 which act as switches opening and closing of which is dependent upon the timing circuit and also on the ambient light level.

The solar cells 1 6 are connected in series with each other and the array as a whole is connected in parallel to the battery 1 8 via diode Dl so that the energy generated by the solar cells serves to trickle charge the battery throughout daylight periods. The solar cells 1 6 also serve to control transistor Q2 whose base is connected to a potentiometer 32 connected in parallel with the cells 1 6. By appropriate setting of the potentiometer 32, the transistor Q2 can be controlled so that it is conductive only when the ambient light is above a preselected level, i.e. so that the motor cannot be energised during periods of darkness thereby disabling the feeder during such periods irrespective of the condition of transistor Q1.

The timing circuit essentially comprises two CMOS 555 timers IC1 and IC2 connected in monostable mode with the output (pin 3) of each connected to the input (pin 2) of the other via resistor-capacitor coupling network 34, 36. The time factor for each timer is determined by the RC network connected to pin 7 and to permit variation, one component (e.g. the resistive component) may be variable. Thus, as shown, the resistive component is selectable by means of rotor switches SW1 and SW2 from a bank of different resistors 38, 40. The time factor T = 1.1 CR where T is the time in seconds, C is the capacitance 42, 44 between pin 7 and the negative rail in farads and R is the resistance 38, 40 between pin 7 and the positive rail in Ohms.

In use, the timer IC2 determines the period over which the electric motor and hence the dispensing device 14 are operable, transistor Q1 being conductive during this time. When IC2 times out, transistor Q1 becomes non-conductive to deenergise the motor and arrest feed dispensing; simultaneously IC1 begins timing to time out a preselected interval after which IC2 is rendered operable again to switch on transistor 01. Thus, IC2 determines the duration of the feed dispensing part of each cycle while IC1 determines the duration of the interval between feed dispensing, subject of course to the condition of Q2 as governed by the ambient light level.

All of the electronic components in the timing circuit as described above and, in particular the timers IC1 and IC2, draw a relatively small current thereby making feasible the use of solar cells to trickle charge the battery. Such an arrangement would not be practicable with many other forms of timer that are commercially available, especially electro-mechanical timers, because the current consumption is too large to make solar cells economically feasible.

Claims (6)

1. A feeding mechanism comprising a food storage and dispensing unit operable to dispense food under the control of a battery powered electric actuator and electrical circuit means controlling operation of the electric actuator to determine the duration of the dispensing cycles and the intervals between such cycles, characterised in that photosensitive means is provided for converting solar energy into electrical energy to effect recharging of the battery and said electrical circuit means comprises solid state timing circuitry to minimise current drain on the battery.

2. A feeding mechanism as claimed in Claim 1 including disabling means responsive to said photosensitive means for overriding the timing means so as to prevent operation of the electric actuator (which may be a DC motor) when the ambient light falls below a predetermined level.

3. A feeding mechanism as claimed in Claim 1 or 2 in which the photosensitive means comprises an array of solar cells.

4. A feeding mechanism as claimed in Claim 3 in which said solar cells are mounted on an exposed surface of the storage unit.

5. A feeding mechanism as claimed in Claims 1 to 4 in which the timing circuitry and the battery are accommodated within the hopper.

6. A feeding mechanism substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.