Carefully choose the "most correct" answer, if there appears to be more than one !
* Linear power-supplies
- Are easier to troubleshoot than swiching-power-supplies
- Are less expensive than switching-power-supplies
- Cannot supply as much power as switching-power-supplies
- Require about the same space requirements as switching-power-supplies
* References to a "Crowbar Circuit" in a power-supply
- Is a misnomer, there is no such thing
- Is a dangerous circuit to employ in a power-supply of any kind
- Is simply an "Over-voltage Protection Circuit"
- Is actually in reference to voltage compensation for the output
* In switching-power-supplies,
- The input circuit of the unit is in reality a power-supply in itself
- There is a switching oscillator in the output side
- Output ripple is easier to filter, due to it being much higher frequency than line frequency
- Choices 1,2, & 3 are all correct
- Only choices 1 & 3 are correct
* Dot-Matrix Printers
- May be impact or non-impact printers
- Are always parallel interface, rather than serial interface
- Are not considered in the same category as the Ink-Jet printers
- Are not considered as possible "Near-Letter-Quality" (NLQ) printers
* In repairing a Dot-Matrix Printer circuit board, the occurrence of a block of 4 sizable transistors
- Is part of the power supply circuit
- Is probably for the LED's, or Instrument Control Panel
- Is probably one of the 4-phase stepper-motor driver circuits
* The presence of a cluster of 9 (or even 24) transistors,
- Is obviously the print-head drivers
- Is simply the control circuits for the carriage motor & paper-feed motor
- Is part of the parallel interface drivers
- Is for one of the motor mechanisms, with voltage & current control
* Laser Printers
- Generate static electricity
- Use photoconductive processes
- Incorporate a heater, called a fuser
- All of the above are correct
* In a switching power supply, the largest transistor, near
the "line-side" of the unit, most likely is the _______________.
* In that same switching power supply, the principle voltage regulation is with feedback from the ___________ circuit.
* The circuit that will "short-out" the output of
a switching power supply, if the voltage starts to exceed the
voltage , is called the ______________ circuit.
* On observing the circuit board of a printer, the occurence of 4 transistors in a group will usually indicate __________________________________________.
* If there are 2 sets of these 4 transistors (or a transistor array in a package), and one set of these 4 transistors is
obviously for heavier current, they would be for the __________ ________________.
* The presence of a cluster of 9 transistors (or even 24) in
a group, are obviously for the________________________.
Power_Supplies.html - SfE-DCS, ddf - 07/20/2001 PSandPtrs.sam - ami-pro - ddf - 07/11/96