The Superb Capacitive Discharge Spot Welder – A Must Build Project For Every Home Hobbyists!

Welcomed back, guys. First of all, anyone of you here ever get involved with the capacitive discharge spot welder before? Well, for those that didn’t hear about it, then you must spare a few minutes, and read through this article… Well, we’ve talking about the characteristic of spot-welder few days ago. The capacitive discharge spot welder is a very superior device, as it provides more control than liner transformer versions. Basically, a very large capacitor is charged to a precise voltage. Then, it discharges through the material to produce a controlled cut. In most of the time, the same device is being used for spot and tab welding. If you want a simple discharge cutting, then you have to take out the controller. By simply connect the audio capacitor directly to a high current rectified DC supply; you can easily turn the discharge on and off. Plus, it’s possible for you to control the duty cycle and frequency too. For your information, this project requires a 1-Farad audio capacitor for storage, where is needed to be connected to its charge… Continue reading

The Universal Lithium Ion Battery Charger

Besides of the mobile phones, the Lithium Ion batteries are becoming increasingly popular, especially in the robotic field. In the past, the robots are normally worked with Nickel-cadmium batteries, but it’s not as convenient as the Lithium Ion batteries did! There are many advantages of using Lithium Ion batteries than other batteries, including: It has high capacity by weight or by volume (It’s about twice of NiCads capacity). The Battery packs are smart (We’re able to control charger settings according to our need). No memory effect is required. Lower self discharge, where less than half of NiCads is. Fast charging speed (You only need about two hours to charge the Lithium Ion batteries that running out of energy to fully charged). For building this universal Lithium ion battery charger, an ATmega8 should be used as the main circuit. In addition, a DC supply is needed, as it capable of providing at least 2 volts more than the max cell voltage. The current and voltage control is managed by a PWM output into a P-channel MOSFET. Furthermore, a large inductor/capacitor combination… Continue reading