I have been told by multiple people variable transformers reduce amps and volts simultaneously, Since transformers reduce amps to increase volts, how is this possible?also, if i want to reduce amps while maintaining volts for a source of 10 amps at 120 volts could i connect a variable transformer and reduce the source to 60 volts and 5 amps, then run that output to a step up transformer at 120 volts and 2.5 amps and then connect this to a 1200 watt electromagnet, will it only draw the 300 watts provided at 120 volts and 2.5 amps? or will it draw as much current as it can?
You were totally lost or you were misguided by someone whom gave you the wrong information on variable transformer compare to a standard transformer. A variable transformer ( we called it auto-transformer ) can raise voltage say from 1V till 145V for a standard 120V power source application. Its output current is limit by its VA rate due to its wire size and core size. Suppose it rated 500VA, then its maximum current limit is 4A. In another word, this transformer can support 4A maximum current from 1V till 145V at any voltage setting. If over 4A load at any voltage between 1V to 145V could burn the coil because it uses one size wire for one coil. Reduce voltage with a transformer does not reduce ampere from transformer. It is the load determine the amperage. You were so confuse again ! Here is an example. 100W lamp draws 0.83A at 120V By reduce the power source into 60V , 100w lamp draw 0.417A It is not the transformer limit its output current into 0.417A. It is the lamp resistance causing current comes down while voltage comes down. From Ohm's law. current E / R As E reduces into half, current passing lamp reduces into half. DO YOU UNDERSTAND NOW ! One more thing to remember.energy cannot be obtained from nowhere, transformer is a voltage exchange device which has no gain. You do not expect obtain extra energy by using transformer.
Simple answer Your house hold items like dvd player tv alarm clock all have a step down VOLTAGE transformer other appliances like a bar heater / toaster hot plate will not be stepped down. Reason being only a voltage transformer is because your home has a line either 240 volts or 110 depending if USA or Australia ect and it stays at that voltage throughout your home. You can also have step down CURRENT (amps) transformers for electronics ect. Step up voltages saves power being wasted so they step it up in transformers and run the power high above the ground and step it down again on electrical poles transformers and substations to distribute it to homes Reason being is OHMS law thinner wires can be used on high voltage because the current is very low , and thicker cables are needed where the current is very high eg a mig welder. I WANT TO MAKE 120 VOLTS AND 10 AMPS 120 VOLTS AND 2.5 AMPS! Answer you can do this 2 ways , cheapest way is to use a resistor in series to step down your current you will need a 48? resistor or a step down transformer
variable transformers reduce amps and volts simultaneously Transformers, variable or otherwise, reduce or increase voltage. The current is determined by the load. So if the load is linear, when you reduce voltage, you will reduce current. transformers reduce amps to increase volts True in one sense, but don't take statements like this to be always true under all conditions. You can use a transformer where you need more current at lower voltage, true. BUT, with a fixed load, if you reduce voltage, you reduce current. Of course, this means the input current is reduced even more. Your last paragraph is totally meaningless, sorry. You apparently have no idea of what voltage and current mean. edit: ALL I WANT IS TO CONTROL CURRENT INDEPENDENT OF VOLTAGE With a given voltage, the current is determined by the load. If the load is fixed, then you cannot vary it except by varying the voltage. PROBLEM IS THE ELECTROMAGNET IS SUCKING TOO MUCH POWER AND OVERHEATING Then you need to increase the number of turns, which will reduce the current. You may need to reduce the wire size also to get the number of turns you need.
