For every piece of home equipment/appliance we bought today, it comes with a power adaptor. For example, DVD player, rechargable tools, home cordless phones. Usaully the adpator has a label that shows the output values. My problem is when something breaks down, I have no way to know whether it's the adaptor that breaks down or the equipment itself. In addition, there are all these terms that I don't understand on the label, like "V", "mA", "VA", "VAC", etc. Here is something on the label for my battery charger:
4.35V 210mA 1.8VA, what are these all mean? Please kindly advise.
These are words created by the almighty to keep woman dependent on man. V is volts. VAC is alternating current type voltage. A and mA are amps and milliamps - the amount of electrons that will flow in that electricity. VA (volt-amps), watts (W), and kilowatts (kW) measure the overall power.
To better understand these 'manly' expressions, get a basic electricity book from the library. That is easier that trying to start learning here. Electricity has two basic parameters
- voltage and current. It flows > For every piece of home equipment/appliance we bought today, it comes with a
1.8 [VA] is the maximum rating of the transformer - so if you need a replacement this is the Minimum *VA Rating* you need you can get one with a larger value
it is the [V] volts, Multiplied, by the [A] amps (V X A)
which for your transformer is 4.35 X 210/1000 (i.e.miliamps) = 0.9135 [VA] which is a lot less than the maximum rating (1.8) for various reasons.
First of all, there are two types of voltage (and current)[Vac] *ac* means that the voltage is alternating between say between + or - 5[V] (although this can practically be any value)
The voltage from your wall socket is [Vac]
The type of voltage and current requirement for the *output* of a battery charger is [Vdc] (note you cannot charge a battery with [Vac]) In this case the value is constant (say, 5volts)
ALL power adaptors are essentially transformers, SO they transform your mains voltage (at the wall socket) to the voltage your appliance wants which in your example is 4.35[V] (Vdc is assumed for a battery charger - i.e. *DC Supply*)
Remember there are lots of different *connector types* at the end of the cable (i.e. the 4.5 volt side) and either the inner or outer pin can be the
*hot* (positive) and this might mean swopping the connection wires (Changing the *polarity*) (or buying one that allows you to do this) to suit the aplliance (the power in socket on the appliance tells you this information - look closely and take a drawing)
Remember when replacing everything is dictated by the connection to your appliance and the appliance power requirement.
Keep the same output voltage [VA] rating must be equal or greater Connector type and polarity must be identical.
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