This small neat unit plugs into a car cigar lighter socket and produces mains voltage electricity to power up to four pyrography machines. We have chosen it rather than other larger inverters as this one gives a particularly long battery life and is tolerant of inductive loads (some inverters will not work too well with a pyrography machine transformer). There is a socket at the rear of the unit which takes the mains plug of the pyrography machine. An extension cable could be used.
Maximum output 200 Watt at 230Volt.
Our measurements show that the unit takes 2 Amps from the battery with one pyrography machine working at normal heat (a good glow) and using the heavy PP11 25 SWG point. It will draw slightly less if you use a finer point and slightly more with a very thick wire point. If you have a 40 amp-hour battery in good condition and fully charged you should get 40/2 equals 20 hours of continuous use. Of course it would be half that with two machines going. With no load (pyrography machines switched off) this unit takes only one third of an Amp giving 120 hours. If your battery has been used in a car for two years or so, expect it to have a diminished capacity - some testing at home might be a good idea with some jumper leads and another vehicle available should you hear the "low battery" alarm on the unit sound! If you are away from home you could start the car every 3 hours or so to give the battery a charge just to make sure you can get home at the end of the day.
Of course it would be best to have a separate battery. You can buy budget 40 Ah car batteries for under £40. You would need a mains charger as well to charge your battery but they are not expensive. You will need to improvise or buy a connector cable with some crocodile clips to clip onto the battery terminals and some way of connecting to the cigar lighter type plug on the inverter. Correct polarity is important. Be very careful that the battery does not tip over or crash into anything while in transit.
This unit produces a modified sine wave output which is absolutely fine with a pyrography machine but it may upset some mobile phone chargers. The makers claim the unit is good for laptops and other electronic equipment but if you want to charge your mobile phone you would be wise to have some additional load (such as a pyrography machine!) plugged in at the same time.
Can ordinary torch batteries be used with the inverter?
This is not recommended but you could hook up a couple of 6 volt lantern batteries in series to get the 12 volts to power the inverter. If you are lucky you will get an hour or so of use out of them which might be enough if you are only switching on the pyrography machine for a minute or so now and then to sign names etc. The alkaline batteries will be by far the best.