GB2496398A

GB2496398A - A power supply

Info

Publication number: GB2496398A
Application number: GB1119332.3A
Authority: GB
Inventors: Stephen Whitelaw
Original assignee: COTSWOLD MICRO SYSTEMS Ltd
Current assignee: COTSWOLD MICRO SYSTEMS Ltd
Priority date: 2011-11-09
Filing date: 2011-11-09
Publication date: 2013-05-15
Anticipated expiration: 2031-11-09
Also published as: GB2496398B; WO2013068740A1; GB201119332D0

Abstract

A power supply 10 includes a battery input 11, a mains input 18, a boost regulator 19 connected to the battery input and the mains input and having an output for providing a DC signal and a DC/AC transducer driver 20 responsive to the DC signal for providing an AC output signal. The supply further includes a controller 21 for monitoring the battery input level and the mains input level and adjusting the boost regulator output in accordance with the respective detected input levels. The power supply is particularly suitable for use with a vehicle such as a boat, in which case the transducer may be an ultrasonic transducer used in an anti-fouling system.

Description

A Power Supply This invention relates to power supplies where power can be drawn from a battery or a mains input such as occurs in caravans or boats for example.

Many vehicles such as boats or caravans have battery supplies which can be used to run devices within the vehicle but also have the facility to hook up to a mains supply, when such a supply is available. In boats, in particular, it is important that the battery level does not drop below a certain minimum, or else it may not be possible to start the engine. It is therefore known to monitor the level of supply available from the battery and to switch off the supply of power to other devices within the boat, in order to maintain batteries at a certain level. For example it is known to supply power to ultrasonic transducers for use in anti-fouling systems for a boat. These require an AC drive and can use a reasonable level of power. Clearly if such devices are switched off unnecessarily fouling of the boat can occur due to the growth of marine life on the whole. Its removal is expensive, The invention consists in a power supply including a battery input, a mains input, a boost regulator connected to the battery input and the mains input and having an output for providing a DC signal, a DC/AC driver responsive to the DC signal for providing an AC output signal characterised in that the supply further includes a controller for monitoring the battery input level and the mains input level and adjusting the boost regulator output in accordance with the respective detected input levels.

This may conveniently be achieved by having respective analogue to digital converters connected to each of the battery and mains input so that the inputs can be monitored.

The controller may be arranged for monitoring the rate of charge of the battery. It may for example be arranged for causing the boost regulator to maintain at least a level of supply on its output, if the battery is still charging.

Conversely the controller may additionally or alternatively be arranged to boost the output of the boost regulator, if the available inputs exceed a predetermined level.

It will be understood that in the context of ultrasonic anti-fouling transducers this means that for a much longer period there is some operative vibration of the hull and that in periods of good supply an over normal amplitude of vibration can be imposed on the hull to overcome any fouling that may have occurred during a period of low operation or switch off.

The invention also includes a method of operating a power supply as set out above wherein the controller varies the boost regulator output within a range in accordance with the level of supply at the inputs. This may be between 50% -150% of the normal operational output. The controller may additionally or alternatively switch off the boost regulator when the supply on the inputs falls below a predetermined level.

Thus the Applicants have realised that by suitably selecting the operating range of the boost regulator, they are able to maintain vibration over longer periods and are able to boost the amplitude of this vibration when it is convenient and necessary. The need for such an approach may be in part determined by a monitoring system such as described in our co-pending application filed today entitled Anti-Fouling System, the contents of which are incorporated by reference.

Although the invention has been defined above it is to be understood it includes any inventive combination of the features set out above *or in the

following description.

The invention may be performed in various ways and the specific embodiment will now be described by way of example with reference to the accompanying drawing, which is a circuit diagram of one embodiment of the power supply.

In the Figure a power supply generally indicated at 10 is illustrated. This power supply is labelled in terms of it being for a boat and having transducers which are driven. This is a particularly effective environment for the power supply described but as indicated previously, the power supply may be efficacious in other environments and for other purposes.

The power supply 10 has a DC input 11 and a mains input 18. These each feed into a boost regulator 19 that in turn feeds a DC to AC transducer drive 20. The DC to AC transducer drive receives a oscillating signal from a microprocessor 21 and the frequency may be varied for reasons given in the above mentioned co-pending application. Each input 11, 18 has a respective associated AID converter 22, 23 that feed a respective signal to the microprocessor 21 indicating the status of their respective supply. The microprocessor or controller 21 generates a control signal on line 24 that is fed to the boost regulator 19. From the inputs fed from 22 and 23 the microprocessor can determine if mains power is available; if the DC batteries are being charged by the mains supply, by a charging circuit not shown and what the relative levels of these supplies are.

If there is plenty of power available, the microprocessor may boost the power supplied to the transducers (or other power consumers) on output 25 particularly if the microprocessor has noted that a previous period of poor supply has preceded the good supply. Equally if battery levels are beginning to drop, but are still at a greater level than is necessary for emergency, then the microprocessor may prolong the period of operation of the transducers by gradually reducing the level of output from the boost regulator 19 or moving it swiftly to near or at 50% of the normal output. If the supply drops below a threshold level, the boost regulator 19 is switched off and an alarm given, This arrangement provides a much more effective operation of the anti-fouling transducers, whilst maintaining battery levels above the necessary threshold. It will be understood that a similar approach could be used for other power consumptive devices on the boat, which are able to function to some degree at lower power levels.

It has been mentioned before this approach is suitable for other situations in which a mixture of battery and mains power may be used and it is desirable to hold a minimum level of battery power available.

Claims

<claim-text>Claims 1. A power supply including a battery input, a mains input, a boost regulator connected to the battery input and the mains input and having an output for providing a DC signal and a DC/AC transducer driver responsive to the DC signal for providing an AC output signal characterised in that the supply further includes a controller for monitoring the battery input level and the mains input level and adjusting the boost regulator output in accordance with the respective detected input levels.</claim-text> <claim-text>2. A power supply as claimed in claim 1 wherein the controller is for monitoring the rate of change of the battery.</claim-text> <claim-text>3. A power supply as claimed in claim 2 wherein the controller is arranged for causing the boost regulator to maintain at least a level of supply at its output if the battery is still charging.</claim-text> <claim-text>4. A power supply as claimed in claim 2 or 3 wherein the controller is arranged to boost the output of the boat regulator if the available outputs exceed a predetermined level.</claim-text> <claim-text>5. A method of operating a power supply as claimed in any of the preceding claims wherein the controller varies the boost regulator output within a range in accordance with the level of supply at the inputs.</claim-text> <claim-text>6. A method as claimed in claim 5 wherein the controller switches off the boost regulator when the supply on the inputs falls below a predetermined level.</claim-text> <claim-text>7. A method as claimed in claim 5 or 6 wherein the boost regulator has an operational output and the range is 50% to 150% of the operational output.</claim-text>