Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

DIY power supply for hobby projects

No matter what electronics project you are building, power supply is important part of it. For quick tests and prototyping it is best to use variable bench power supply which could be reused for different purposes. If you are serious about electronics, probably it is best to invest in to good bench power supply. But this is also fun to build one by yourself. Abhishek decided to make pretty simple power supply that would fit his needs. He decided to use linear voltage regulators to get needed voltages. So first state he made was stepping down 220V to 20V DC which then could be regulated with linear regulators. He decided to make 5V and 12V by using 7805 and 7812 regulators. Then he used another LM338 to get variable voltages from 1.2V to 25V. Using separate regulators gives ability to drive higher loads in parallel. He also wanted some feedback, so he used Atmega8 which drives an LCD. Microcontroller ADC takes voltage and current readings and displays on screen. He uses a shunt resistor to read voltage drop from current.… Continue reading

Using DIP switch to select voltage you need

In many cases you simply need a voltage source that could be used right away. It may be 5V, 3V or other like. Many battery operated electronics require voltages that are multiply of 1.5V – single cell. So for instance if device requires 4 AA batteries then it total voltage is 6V. Jason is a fan huge of garage sales where he can find lots of ideas and materials for his projects. But he wants to make sure if devices works properly before purchase. Due to variety of battery types he didn’t want to carry a bag of batteries around. So he came up with nice idea p DIP switch controlled power supply. As you can see there is nothing actually new or extraordinary. An LM317 power regulator is used to adjust voltage to right level. DIP switch seems to be convenient way of selecting the voltage. Each switch is connected through resistor that allows adding 1.5V per step. Supply is powered from 9V battery. So this makes useful battery replacement. Output wires have alligator clips to connect to device… Continue reading