Rechargeable NiCd (nickel-cadmium) cells are widely used in consumer devices because of their high energy density, long life, and small self-discharge rate. As a part of one project, I needed to design a reliable and inexpensive charger for a battery pack containing two NiCd AA-size 1200-mAh cells. In the process of the charger design, I …
Charge a nickel-cadmium cell reliably and inexpensively Read More »
This Instruct able is about dry film solder mask, in other words, is the green stuff that is on top of the circuit board. I like to use smd components in my circuits board because I don’t have a computerized drill machine and do in it by hand for a big boards are really tedious. …
Yesterday I saw the “The Practical Meter” on Kick starter – a small unit that is placed inline with the USB when charging your phone and shows the actual charging power (in watts) on a row of LEDs. I wanted to have a go at it as well so I did the following last evening. …
A well known reliable PCB relay can be now found in our store in the version V23084-C2002, fully usable in demanding automotive applications. Previous version of widely used relay V23084-C2001 we introduced to you in the article Automotive relay for PCB used by leading world producers. However after many years of production this relay has …
Introduction: A voltage step-up is a circuit that increases the voltage. It can be AC/AC, AC/DC, DC/AC or DC/DC. This voltage step-up is a DC/DC adjustable voltage regulator. Usually a voltage regulator is fed by a higher input than output voltage, for example 9V IN to 5V OUT. This circuit will take a low voltage …
Adjustable Voltage Step-up (0.7-5.5V to 2.7-5.5V) Read More »
Combining Arduino and other shield modules, we make a mobile phone named Arduino Phone. Meanwhile, we printed a shell for it with the 3D printer. Although it’s not such fine as you think, even a little bit clunky, it’s still very cool. That is the point this is a cell phone made by ourselves. While, …
Creating a solder paste stencil for a toaster reflow oven or hot plate is simple when you have access to a laser cutter. I used the Laser Cutter at my local Tech Shop to create this and other PCB stencils. This Instruct able assumes you have created a PCB and are able to generate the …
The reason for this project was to solve a problem I have. I sometimes do several days of hiking/backpacking in the wild and I always bring a smartphone with GPS and maybe other electronics. They need electricity and I have used spare batteries and solar chargers to keep them running. The sun in Sweden is …
Aurora 48 is capable of individually controlling 48 Full color LEDs using a 40 pin microcontroller. The principle of operation is based on my other “Aurora’s. (see Aurora 9×18) The circuit is relatively simple and straightforward. If you’ve seen other LED matrix type circuit, this should look familiar. In a nutshell, the 48 RGB LEDs …
Properly maintained rechargeable batteries can provide good service and long life. Maintenance involves regular monitoring of battery voltage. The circuit in Figure 1 works in most rechargeable batteries. It comprises a reference LED, LEDREF, which operates at a constant current of 1 mA and provides reference light of constant intensity regardless of battery voltage. It …
