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Each of the 12 Power MOSFETS on this board can dissipate up to 80 watts of power. Because they are not mounted to heat sinks you won't be able to squeeze quite that much power out of them, however, this configuration should be more than adequate for any reasonable stepper application. (A typical 100 oz in stepper only draws about 10 watts per phase.) Note: for an extra $18 you can special order the FET-3 with 36 amp, 140 watt MOSFETS! These MOSFETS are absurdly over-powered, however, they will run more efficiently and cooler. The internal resistance of these devices is a mere .04 ohms, which makes them a near-perfect device for switching power. What does all this mean for your application? Most Stepperworld customers don't need anywhere near the power we're talking about. However, you may want something more than the 1.25 amps of the SP-3, which is designed for smaller applications such as a Sherline or TAIG mill which use 60-80 oz in motors. With the new FET-3 you can efficiently drive the light duty motors, but you can also move up to real power! This approach allows you to start modest but leave yourself plenty of headroom. Stepperworld customers with original SP-3 systems (Shinano Motors powered at 5v) who upgrade to the FET-3 will see an immediate 20% increase in motor torque. MOSFETs have so little internal resistance the entire supply voltage is delivered to the motor, instead of being diminished by the older Darlington-type transistors. (With a 5 volt supply, a typical Darlington transistor will drop about 1 volt.)
By popular demand, Stepperworld introduces the FET-4, four axis stepper controller. The FET-4 is essentially a four axis version of the FET-3. Control four axis from one parallel port. Accomodates 4 switch inputs for home/limit positioning, and 2 aux outputs. (To turn an AC load ON/OFF we recommend this opto-coupled Power Relay.) Optional MOSFET upgrade for the FET-4 is $24. Pricing Purchase the FET-3 by itself for $135. (Optional MOSFET upgrade $18.) Includes Parallel Cable and Software CD. Does not include motors, power supply, source code that you get when you purchase a complete "system". Purchase the FET-4 by itself for $175. (Optional MOSFET upgrade $24.) Includes Parallel Cable and Software CD. Does not include motors, power supply, source code that you get when you purchase a complete "system". Purchase any FET-3 system ( FET-3/Cruiser FET-3/Hobbyist FET-3/Dynamo) and you can upgrade to FET-4 board for only $50. Motors We have a selection of high torque motors (starting at 100 oz in) ideal for use with the FET-3 and FET-4. Please contact admin@Stepperworld.com for details about current motor stock. Visit the www.Stepperworld.com web site |
