3-68. Figure 3-41, view (A), shows the normal bias arrangement for the UJT. A positive

10 volts is placed on base 2 and a ground on base 1. The area between base 1 and base 2

then acts as a resistor. If a reading were taken between base 1 and base 2, the meter would

indicate the full 10 volts (see Figure 3-41, view (B)). Theoretically, if one meter lead were

connected to base 1 and the other lead to some point between base 1 and base 2, the meter

could read some voltage less than 10 volts (Figure 3-42, view (A) shows this concept).

View (B) also shows the voltage levels at different points between the two bases. The

sequential rise in voltage is called a voltage gradient.

3-69. The emitter of the UJT can be viewed as the wiper arm of a variable resistor. If the

voltage level on the emitter is more positive than the voltage gradient level at the emitter-

base material contact point, then the UJT is forward biased. The UJT will conduct heavily

(almost a short circuit) from base 1 to the emitter. The manufacturer fixes the emitter in

position. The level of the voltage gradient therefore depends upon the amount of bias

voltage (see Figure 3-43).

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