Electronics Project Circuits
Welcome to our projects section. We have created the tutorials here to expand the circuits in our Electronics Starter Kits, most of the circuits you can build with the components supplied in the starter kits, while some circuits will require a few additional components.
All the circuits come with a step by step guide and a downloadable PDF sheet, this allows you to quickly expand the booklet supplied with the Electronics Starter Kit.
555 timer Dual Flashing LED
Building on from experiment 5 where we use a 555 timer to create a flashing LED we can also use that circuit to create a dual alternating flashing LED.
In experiment 5 555 timer flashing LED we use the output from pin 3 of the 555 timer to flash the LED when pin 3 is high, the LED is connected to the negative power and then to pin 3 through the resistor. We can also use the output of pin 3 when the output is low to create an alternating pair of flashing LEDs.
When the output of pin 3 is high the LED and resistor are connected to the negative power, if we want to use the output when pin 3 is low we need to connect a resistor and LED to the positive power.
We are still using the 555 timer in astable mode and we can use the calculations below to alter the resistors and capacitor to control the timing of the high, low and time period.
- The frequency is the number of pulses per second
- The time period is the time covered for one pulse, output high + output low
- The duty cycle is the ... more
555 timer Flashing LED
In this experiment we are going to use a 555 integrated circuit to create a flashing/blinking LED. The 555 integrated circuit is commonly referred to as a 555 timer and can be used in astable, bistable or monostable mode.
When you see a flashing LED in a circuit it’s almost always the work of a 555 timer, although the 555 does have a lot of other application uses.
In this circuit we are going to be using the 555 timer in astable mode. When the 555 timer is astable it produces a square wave output and alternates between VCC and 0v on a continual basis. This type of circuit is called astable because it is not stable in any state; the output is continually changing between low and high.
The values of R1, R2 and C1 we can determine the period/frequency and the duty cycle. The period is the length of time it takes for the on/off cycle to repeat itself and the duty cycle is the percentage of time the output high.
Increasing C1 will increase the period time (reduce the frequency)
Increasing R1 will increase the time the output ... more
LDR Darkness Sensor Circuit
This circuit uses an LDR (Light dependent resistor). The resistance in an LDR is variable and as light falls upon it, the resistance decreases. The resistance in a typical LDR can fall from 1M ohm to 5K ohm.
When combining an LDR with a Transistor which is being used as a switch we can use these to turn on a light as darkness falls. This can be used in a Variety of applications, such as a camera shutter controller, security light, Childs night light and automatic lights on a car or boat.
The components that we are going to need for this experiment are listed below and we have put a link and product number next to each one for quick reference:
