BASIC ELECTRONICS - OD1633 - LESSON 1/TASK 2
resistance is now equal to the resistance of R1, or 20 Ohms.
As you know, R2 and R3 form a parallel network.
Resistance of The network
can be calculated as follows:
R2 = 100 Ohms
R3 = 0 Ohms
The total circuit current with R3 shorted is 6 amps. All of this current
flows through R1 and would most likely damage R1. Notice that even though
only one portion of the parallel network was shorted, the entire parallel
network was disabled.
Opens and shorts alike, if occurring in a circuit, result in an overall
change in the equivalent resistance. This can cause undesirable effects in
other parts of the circuit due to the corresponding change in the total
current flow. A short usually causes components to fail in a circuit which
is not properly fused or otherwise protected. The failure may take the form
of a burned-out resistor, damaged source, or a fire in the circuit
components and wiring.
Fuses and other circuit protection devices are installed in equipment
circuits to prevent damage caused by increases in current.
protection devices are designed to open if current increases to a
with the circuit or portion of the circuit that the device is protecting.
When the circuit protection device opens, current flow ceases in the