InductionHeater

Project InductionHeater
Status	Initializing
Contact	smeding, gori
Last Update	2014-09-08

Idea is to make a 3kW induction spool to smelt metals and heat steel for forging. For examples see :

• [1]
• [2]

Inverter circuit

Smeding came up with the following circuit:

Values of all components are to follow shortly. The accompanying BOM looks something like this:

Component	cost
Bridge rectifier	€2.56
switching transistor	€22.92
Tank capacitors	20.50
DC link filter capacitor	€23.14
Gate driver	€7.06
Couple transformer Toroid	€20 (est.)
Gate drive transormer toroid	€3
Estimate for components killed (see below)	€60
Total	€160

Based on Smedings estimate Obviously, some parts may die a gruesome death during construction and testing. Worst case estimate is that the switching transistor and the driver will die twice, adding an amount of €60 to the BOM before we have a working machine.

Additional hardware

In addition to the inverter circuit, at least the following things are needed to make a working induction heater

Component	cost	Possible sources	requirements
Coil 1 small diameter for smelting	€ 15 ?	Gas tubing, car brake tubing	Copper. Sufficient copper area to handle the current. Sufficient inner area + diameter to allow for effective cooling
Coil 2 large diameter, 30cm for forging, between 5 and 10m	€ 25 - 50	Gas tubing, 15 mm car brake tubing	Copper. Sufficient copper area to handle the current. Sufficient inner area + diameter to allow for effective cooling
heat exchanger	€15 ?	Car junkyard	Unsure how much heat needs to be removed and at what temperatures. Worst Case would be 3 kW. A car radiator is probably good (cheap, sufficient power and an integrated fan)
Pump	€20	Possibly a pump from a domestic heater (CV). Buy for around €20 on Marktplaats	Have to check whether or not normal sizes create sufficient flow through small diameter coil tubing
Electrical connections and wiring	€ 20	Battery connections form scrapped cars?	How much current do we expect, and how long do the wires have to be? how do we connect these to the coil tubing (Earth blocks?
Tubes and other cooling connectors	15€
...
Total cost	€ 85 (incomplete)

Total cost

	cost
Inverter	€160
Hardware	€85
Total	€245

Now we need financing. The current total is €245, and that isn't complete so far (although it may get close)

Pledges:

• Gori: 50 euro
• Flok: 10 euro
• Walter: 50 евра
• FooBar: €20
• bertrik: €10
• Semafoor: €20 (more if the project is better defined)