Educational Publishing for Design & Technology


Discovering Digital Electronics


Discovering Digital Electronics is an online course which will give you an excellent understanding of the fundamentals of digital circuits. This isn't just a matter of reading about how things are supposed to work. There is plenty of clearly explained and fully illustrated practical work to help you put the theory into context, developing your knowledge and enhancing your constructional skills.

As part of the course, you can learn about and build the DOCTRONICS Digital Clock. This uses 4000 series logic integrated circuits, ICs.

DOCTRONICS digital clock
DOCTRONICS digital clock

The Digital Clock kit is no longer available.

To follow the practical work, you will need to buy electronic components and a few essential tools. All of these are available from Rapid logo Rapid, the UK's leading electronics supplier to schools. Click the links provided to reach the website. It is quick and easy to open an account. Rapid offers good value, even for small orders, and lives up to its name by sending you your order promptly, often arriving the next day.



Chapter 1 1 : BEGINNINGS
What are digital circuits? Find out how to generate logic signals. Build and understand circuits using prototype board. Use a multimeter to make voltage measurements. Find out about LEDs and transistors and build logic level indicator circuits using these components.
Chapter 2 2 : LOGIC GATES
Find out about 4000 series and 74 series logic ICs. Experiment with the 4011 quad
2-input NAND gate IC. Use NAND gates to drive LED indicators. Build other logic gates using NAND gates. Investigate truth tables for NOT, AND, OR, NAND, and NOR gates. Develop a NAND gate circuit which obeys the truth table for EXOR. Experiment with the 40106 Schmitt trigger NOT gate IC and use it to make a simple astable.
Chapter 3 3 : ASTABLES
Learn the theory of charging and discharging capacitors and find out about the pulse response of RC networks. Build the circuit of a simple NOT gate astable and modify it to change the mark space ratio. Find out about gated astables and pulse completion. Experiment with ring-of three astables and explain why these give improved performance. Find out about astables with two RC networks. Discover Schmitt trigger and crystal-controlled astables.
Chapter 4 4 : MONOSTABLES
A monostable produces a single pulse when triggered. Build edge detector/half monostable circuits using Schmitt trigger logic gates. Explore switch debouncing and power on RESET circuits. Find out about NAND gate and NOR gate monostables. Understand retriggerable monostables and experiment with the 4538B dual precision monostable IC.
Chapter 5 5 : BISTABLES