TPC 252 Flashcards
Power supplies can receive ______ as an input and can deliver______ as an output.
AC or DC; AC or DC
One possible function of a power conditioner added to a power supply is to ______ the ______.
Regulate; Frequency
An oscillator-driven inverter:
Produces a sine-wave output
A voltage regulator changes its’ ______ in response to changes in the ______.
Resistance; Power drawn
Low voltage can be as lethal as high voltage, because the damage is done by the:
Current passing through the body
The essential parts of an electrochemical cell are the _____ and ______.
Electrolytes; Electrodes of different metals
Among carbon-zinc cells, the ______ cell works better than the Lectanche cell for continuous use, but not as well for intermittent use. However, the ______ cell has a longer shelf life than the lectanche cell.
High energy; Alkaline
A 12 V automotive (lead acid) battery is overcharging if the voltage between the terminals is more than _____ volts while the engine is running.
15.0
To protect yourself when working with cells and batteries, you should always be aware that the:
Battery may produce explosive gases
The best way to provide electricity at remote microwave relay stations is to install ______ cells.
Photoelectric
The maximum forward current in most diodes causes a forward voltage drop of ____V.
1.0
If necessary, you can temporarily connect two diodes in parallel to provide the necessary _______ in a circuit. Diodes can be connected in series to provide the necessary ______.
Current; Voltage
A forward biased SCR ________ current until a trigger pulse passes from the _______ to the cathode.
Blocks; Gate
The peak-to peak voltage across the secondary of a transformer is 50V (from -25V to +25V). If a half wave rectifier is connected to this secondary, the range of its’ output will be ______, less the diode drop. A full-wave rectifier (not a bridge rectifier) connected to this secondary will produce an output in the range ______ less the diode drop.
0 to +25 V; 0 to +12.5 V
In a voltage multiplier, the output of the _____ is the input to the ______. Their outputs combine to produce the higher voltage.
Diodes; Capacitors
The power supply to an audio circuit delivers an output that oscillates between +48 and +52 V at 60 Hz. What is the percent ripple in the audio circuits power input?
2.8
In a power supply, the function of a capacitor is to _____ energy.
Store and release
An advantage of an LC filter in a power supply is its’ _____. A disadvantage is its’ ______.
Low ripple; High cost
A bleeder resistor connected between the terminals of a power supply should have ______ resistance. It’s purpose is to ______.
High; Discharge the capacitors
The purpose of using external bypass filters in addition to the filters in a power supply is to:
Prevent interference among circuits on a PCB
A shunt voltage regulator maintains a constant voltage across the load by varying the ______ a path parallel to the load.
Current in
In a series regulator, the control circuit must keep the transistor _______ in order to maintain constant voltage across the load.
Forward biased
One of the most common types of IC voltage regulators has three terminals and is available in the most common preset voltages, ranging from _____ to _____ V.
5-24
A switching voltage regulator operates by switching rapidly between:
Full off and full on
