As an electronics technician, I could pretty much count on visually inspecting a circuit to determine what parts did what, and which ones were bad. Transistors have always been tiny, but, if a device handled lots of power, like a motor control board in an appliance, or even a home stereo's power amp, the solid-state components that actually handled the juice were pretty big. If you couldn't find the transistors, just look for their heatsinks and other thermal handling components. These big pieces of silicon were always expensive, around $10.00 or so. (re-finaling a typical home stereo amp was about a $150 job) It's always the priciest silicon in a solid state device that ends up failing the most, so I would always just look for the biggest semicondustors, and test them first.
This, however, throws this notion out with the 8-track deck and the CB radio: Just today, we received a shipment in of these TINY little FET switching transistors for a job that could handle 87 amperes at 40 volts without a heat sink! These things are small, if an ant was crawling across the printed circuit board, chances are, it could fall in love with one of these things because it's about the same size and shape! The best part about this? A gross order of these things has the price sitting at about. They don't even solder through the board, but just sit "surface mounted" right on the board traces. Spec's from the manufacturer state that the pieces can safely operate in environments up to 150 degrees centegrade, which is also much warmer than typical old-school transistors. The way it's able to handle such enormous amounts of power is through it's low "on" state resistance of less than .05 ohms....or less resistance than a typical mechanical switch! Lower resitance, or course, means less heat dissapation.
Now, these are not made to handle analog signals, but are designed for switching capabilites. Their switching speed is so fast however that they will have no problem handling a pulse-waveform speed controller (PWM) like what is used in many modern appliances. The durability of these things is incredible. If technology exists like this and for this cheaply, it's not going to be any time at all before the mechanical timer is history! This could usher in an amazing flood of new technology in our homes!
This, however, throws this notion out with the 8-track deck and the CB radio: Just today, we received a shipment in of these TINY little FET switching transistors for a job that could handle 87 amperes at 40 volts without a heat sink! These things are small, if an ant was crawling across the printed circuit board, chances are, it could fall in love with one of these things because it's about the same size and shape! The best part about this? A gross order of these things has the price sitting at about. They don't even solder through the board, but just sit "surface mounted" right on the board traces. Spec's from the manufacturer state that the pieces can safely operate in environments up to 150 degrees centegrade, which is also much warmer than typical old-school transistors. The way it's able to handle such enormous amounts of power is through it's low "on" state resistance of less than .05 ohms....or less resistance than a typical mechanical switch! Lower resitance, or course, means less heat dissapation.
Now, these are not made to handle analog signals, but are designed for switching capabilites. Their switching speed is so fast however that they will have no problem handling a pulse-waveform speed controller (PWM) like what is used in many modern appliances. The durability of these things is incredible. If technology exists like this and for this cheaply, it's not going to be any time at all before the mechanical timer is history! This could usher in an amazing flood of new technology in our homes!