ELECTRICITY AND ELECTRONICS WORK    The design and construction of items which will be connected to the mains supply where the use of electricity is peripheral (eg, lamps) or fundamental (eg, low-voltage power supplies for electronics).   Process(es) covered: Instruction in the repair and maintenance of high-voltage equipment. The construction of electronics circuits from prepared modules […]

I wanted to create a couple of circuits using 555 timers and 4017 decade counters but I seem to have hit a brick wall in trying to obtain any 4017s! Rapid look through equivalent chips with Dean and it looks like I can use a 4028 chip instead. A 4028 is officially known as a BCD […]

Now we get to have a little fun… I’m going to take a look at the 3 types of circuit you can make with a 555 timer, astable, monostable and bistable. Monostable – one stable state This is my monostable circuit and I’ve calculated that I need a 100K resistor with my 100µf capacitor to […]

Before starting any experimentation, even if it’s just prototyping on breadboards you need to think about… Seeing yourself as a giant resistor. Sounds a bit silly right? It’s true though, the human body does have some resistance to electric current. To stay as safe as you can when working with electronics you need to think […]

Brilliant session with Dean today, loads to add… First, the Darlington driver or Darlington pair. You basically feed the emitter of one NPN transistor to the base of another, this multiplies their individual current gains so massively boosting the signal. Darlington pairs can be used like this to convert analogue signals to digital ones. If you had […]

I’ve moved on a bit since the last time I looked at logic gates so I think it’s about time to revisit… I’ve found out a bit more on NOT gates, they are actually called inverters, not surprisingly as they ‘invert’ the input into the output. When you connect up two inverters in series you […]

Digital ICs are classified into logic families depending on how they’re constructed on the inside. Some construction methods make the circuits run faster or work using lower currents or just by being able to fit more gates in. There are loads of logic families but the two most famous (and the ones I’ll likely be using) are […]

One thing that has kept coming up in my research has been the term Boolean algebra or Boolean logic, this apparently is a system of logic that was developed in the 1840′s by a chap called George Boole. It basically laid out several rules of relationships between mathematical quantities that were limited to being true […]

If I’m going to teach electronics (or even develop my interest as a hobby) there are three ICs that I will have to look at. They are the op amp (operational amplifier), the 555 timer and the 4017 decade counter. Op Amp – this IC takes a weak signal and gives it a boost, it’s made up […]

Ok, so I don’t have to create a PCB for each circuit I want to explore I’m going to have to look into methods of circuit prototyping… The first to come to mind (and to hand sitting at my laptop ) is a program called Circuit Wizard, I’ve already used this in previous posts to […]