Contrast a decoded Johnson decade counter with a 4-bit BCD (Binary Coded Decimal) ripple counter. Describe one functional difference and one functional similarity in how they output or sequence through their counts.

An astable oscillator produces a continuous train of pulses shown on the oscilloscope screen below:

Draw on this

In each complete cycle, the signal is high for exactly 2 horizontal grid divisions and low for exactly 6 horizontal grid divisions.

The oscilloscope settings are:

• voltage gain $=2V\; /\; division$
• time-base $=12.5\mu s\; /\; division$

Determine the duty cycle and frequency of this signal.

The astable oscillator is adjusted to produce a 2500 Hz test signal.

This signal is applied to the clock input of the BCD counter and to the clock input of the decoded Johnson decade counter.

The outputs of the BCD counter are $Q_0,Q_1,Q_2$ and $Q_3$, where $Q_0$ is the least significant bit (LSB). The outputs of the decoded Johnson decade counter are $Q_0,Q_1,Q_2\dots Q_9$.

Determine the frequency of the pulses available at $Q_1$ for each counter.