Inverter Advice
Power Inverters, An Introduction
A power inverter takes a direct current low voltage input, as available from car and lorry batteries and converts this power both up in voltage and to an alternating current, as available from the household mains supply. This allows many household appliances which are normally powered from the standard mains supply to be used away from home, by effectively powering them from 12volt or even 24volt batteries.
The latest generation of inverters comprise a unique combination of state-of-the-art design in two areas:
1) transformer technology, and 2) power electronics.
The inverters we supply are suitable for most equipment within their maximum continuous power and can be used with televisions, computers, portable power tools, lighting, fax machines, medical equipment, nebulizers, battery chargers, video’s, cash registers, satellite receivers, hi-fi’s, central heating pumps, food mixers, and many more. When selecting the inverter allowances must be made for the equipment’s starting surge. Usually, you will require the inverter that has a continuous maximum power that is approximately 50% above the power rating of the appliance. For reliable operation, the wiring of the 12 volt input to an inverter can be very critical. If in doubt please contact us to discuss your requirements and for general advice.
Most inverter designs are of the ‘Modified Sine or Square Wave’ type, these generally give good performance together with lower cost, but due to the output waveform shape can cause interference with some equipment and do not give maximum efficiency in the power conversion from D.C. to A.C. Most mains powered equipment is designed to operate from and work at its most efficient when supplied with a pure sine wave A.C. voltage which a ‘True Sine Wave’ type inverter provides. The absence of sharp rising edges found in modified sine wave and square wave outputs eliminates interference in audio, video and electronic equipment. Motor loads start easier and run cooler and quieter without the extra harmonic distortion from modified sine wave inverters. Until recently these inverters have been very expensive, used mainly in commercial and utility applications.
Many of the inverters are for general purpose use, however we also supply inverters for specific applications, such inverters are tailored to equipment such as satellite receivers, televisions and portable computers.
Determining Battery Size
To obtain the time allowed from a given battery before recharging is necessary divide the power of the appliance connected to the inverter by 10 to give the load current of the inverter. Divide the Ampere-hour(Ah) rating of the battery by the load current. The answer is the time allowed in hours. e.g. An inverter is running a 60 Watt television and requires a load current of 60 divided by 10 = 6 Amps. The battery is 75 Ah and the time allowed is 75 divided by 6 = 12.5 hours.
Below are some useful equations:
Time (hours) allowed =
battery capacity (Ah) divided by load current (A)
Battery (Ah) capacity =
time (hours) required multiplied by load (A) current
Load (A) current =
power rating of appliance (W) divided by
((10 for 12 volt) or (20 for 24 volt))
A power inverter takes a direct current low voltage input, as available from car and lorry batteries and converts this power both up in voltage and to an alternating current, as available from the household mains supply. This allows many household appliances which are normally powered from the standard mains supply to be used away from home, by effectively powering them from 12volt or even 24volt batteries.
The latest generation of inverters comprise a unique combination of state-of-the-art design in two areas:
1) transformer technology, and 2) power electronics.
The inverters we supply are suitable for most equipment within their maximum continuous power and can be used with televisions, computers, portable power tools, lighting, fax machines, medical equipment, nebulizers, battery chargers, video’s, cash registers, satellite receivers, hi-fi’s, central heating pumps, food mixers, and many more. When selecting the inverter allowances must be made for the equipment’s starting surge. Usually, you will require the inverter that has a continuous maximum power that is approximately 50% above the power rating of the appliance. For reliable operation, the wiring of the 12 volt input to an inverter can be very critical. If in doubt please contact us to discuss your requirements and for general advice.
Most inverter designs are of the ‘Modified Sine or Square Wave’ type, these generally give good performance together with lower cost, but due to the output waveform shape can cause interference with some equipment and do not give maximum efficiency in the power conversion from D.C. to A.C. Most mains powered equipment is designed to operate from and work at its most efficient when supplied with a pure sine wave A.C. voltage which a ‘True Sine Wave’ type inverter provides. The absence of sharp rising edges found in modified sine wave and square wave outputs eliminates interference in audio, video and electronic equipment. Motor loads start easier and run cooler and quieter without the extra harmonic distortion from modified sine wave inverters. Until recently these inverters have been very expensive, used mainly in commercial and utility applications.
Many of the inverters are for general purpose use, however we also supply inverters for specific applications, such inverters are tailored to equipment such as satellite receivers, televisions and portable computers.
Determining Battery Size
To obtain the time allowed from a given battery before recharging is necessary divide the power of the appliance connected to the inverter by 10 to give the load current of the inverter. Divide the Ampere-hour(Ah) rating of the battery by the load current. The answer is the time allowed in hours. e.g. An inverter is running a 60 Watt television and requires a load current of 60 divided by 10 = 6 Amps. The battery is 75 Ah and the time allowed is 75 divided by 6 = 12.5 hours.
Below are some useful equations:
Time (hours) allowed =
battery capacity (Ah) divided by load current (A)
Battery (Ah) capacity =
time (hours) required multiplied by load (A) current
Load (A) current =
power rating of appliance (W) divided by
((10 for 12 volt) or (20 for 24 volt))