A simple LED Volt Meter using Zener diodes as switches. If it is connected to a 12 Volt battery it shows the following indications.
Flash LED Blinks – Above 13 volt – Fully charged
Green LED lights – Above 11.8 V
Yellow LED lights – Above 11.5 V
Red LED lights – Above 10.6 V
If all LEDs light, battery voltage is above 13 volt and fully charged
Fun! Light an LED briefly by tapping on a Piezo element used in the buzzer. Enjoy the wonder of lighting the LED by your finger tapping on the Piezo element. Piezo electricity is the natural electricity generating from Piezo ceramic material. Piezo ceramic material like Lead Ziconate Titanate has the property to generate a tiny current when its crystals are mechanically disturbed through pressure or heat. At the same time, if a voltage applied to the Piezo ceramic material, it vibrates. This property is used in Piezo buzzers to generate sound.Let us see the Fun
You can light an LED without a battery! It is funny to see that, the LED is glowing without power from a battery. The trick is Wireless electricity that is lighting the LED through the mechanism of Induction. Many projects are available in You tube and selected one simple project for you. The step wise procedure is explained here. You can learn some theory along with this. Make it and enjoy.
After assembling the circuit on the Etched PCB or Perf board, we need a PCB tester to troubleshoot the problems if any. We can test the points on the PCB using a Multimeter to confirm whether current is arriving or not. But this handy tester will give an Audio visual indication. It beeps and lights LED when there is current flow in the test points. It can also be used as a Battery tester. If more than 2V is present in the battery, buzzer beeps and LED lights. If the battery is flat, the tester remains silent.It is a good tool, so learn to build this as your start up project.
Starting some simple projects for the beginners who are going to start the electronics project building. The first project is a simple LED Tester without any soldering. You can make it in few minutes. With this tester you can check all the LEDs and can also be used as a Light source.
Here is a simple Portable Power Bank that finds many uses. It can be used as a Portable Mobile Charger or it can be used for powering the bread board projects and so many applications that requires 5V Regulated DC. Let us make it.
This circuit tells you how much radiation is coming from electric devices. It picks up the AC hum from the surroundings of electric equipment and electric wiring and blinks the LED to show the radiation level. You can also use this to assess the safe distance from Computer radiation.