Low-Volt | Electronic Project Circuits

Posts Tagged ‘Low-Volt’

Low volt LED Flasher

In the circuit diagram for the Joule Thief, the common point of the toroid is the connection at the top of the hand-wound ferrite toroid, in the upper right of the diagram. This goes to the positive end of the battery. The other two wires from the toroid go to the resistor and to the intersection of the transistor with the LED.
One other detail that you may need to know is the symbol and pinout of the 2N3904 transistor. In the symbol, the part with the arrow is the “emitter”, the “collector” is the end above it, that also connects to the LED, and the “base” is the wire leading off to the left, between the collector and emitter. (Also remember that the end of the LED with the flat side and short lead is the end that has the flat bar in the diagram.)

Read More Source: http://www.evilmadscientist.com/article.php/joulethief
Thank you.

Be the first to comment - What do you think? Posted by admin - June 2, 2008 at 10:25 am

Categories: LED Flasher Tags: 2N3904, current lightning, led display, Low-Volt

1.2 – 12V 1A Low Voltage LED Indicator Power Supply by LM317

This is a 1.2 – 12 V, max 1A power supply with a low voltage indicator LED. The indicator part incluedes three diodes and one LED. For example you are charging a battery, you can observe the charge status at that moment. Another advantage of this circuit, when the drawn current exceeds 1A (practically 0.85A), the current protector in LM317 intervens and LED indicator warns you about the very low output voltage.

Read More Source:http://www.circuit-projects.com/12-12v-/-1a-low-voltage-led-indicator-power-supply-by-lm317.html

Be the first to comment - What do you think? Posted by admin - January 24, 2008 at 7:10 pm

Categories: Power supply, Variable Regulator Tags: led voltage indicator, LM317 power supply, Low-Volt, Variable Regulator

5V Low Drop Out Regulator Low Volt by BD438

I have a 6V battery, but it needs to be applied to digital circuits that used to 5 volt regulated.
In first, I will reduce this voltage with a single resistor, but the load current is not constant.
The other way to use is a second, I would use 2 x 1N5402 diodes to connected in series to reduce the voltage to the load. But it don’t work because low current output.

I selected this simple circuit is the 5V Low Drop Out Regulator Low Volt. It used normal electronics part are transistors and resistors. While we can adjustable the P1 for control output voltage at current 500mA.

When the BD438 transistor Q1 is very hot, so the cooling pad. And we use numbers instead TIP3055 number 2N3055 (easy to buy all the time).