battery charger , charges at maximum current

Battery charger at maximum current



I built this charger using the circuit from:
http://www.extremecircuits.net/2009/12/unlike-many-units-this-battery-charger.html

Unlike many units, this battery charger continuously charges at maximum current, tapering off only near full battery voltage. In this unit, the full load current of the supply transformer/rectifier section was 4.4A. It tapers off to 4A at 13.5V, 3A at 14.0V, 2A at 14.5V and 0A at 15.0V.

Might not be the most elegant build , but it works , the heat syncs are a bit over sized but Im planning to upgrade the transformer to 5 amp , Im also going to add a volt and amp meter.











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Circuit operation:

Transistor Q1, diodes D1-D3 and resistor R1 form a simple constant current source. R1 effectively sets the current through Q1 - the voltage across this resistor plus Q1's emitter-base voltage is equal to the voltage across D1-D3. Assuming 0.7V across each diode and across Q1's base-emitter junction, the current through R1 is approximately 1.4/0.34 = 4.1A. IC ensures that Q1 (and thus the constant current source) is turned on.

When the battery has fully charged, the current through IC drops to a very low value and so Q1 turns off (since there is no longer any base-emitter current). R2 limits the current through IC. It allows enough current to flow through the regulator so that Q1 is fully on for battery voltages up to about 13.5V. Decreasing the value of R2 effectively increases the final battery voltage by raising the current cutoff point. Conversely, a diode in series with one of the battery leads will reduce the fully-charged voltage by about 0.7V.

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Circuit diagram:

12 Volt Car Battery Charger Circuit Diagram

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Parts:

Resistors
R1 = 0.32R
R2 = 8.2R

Capacitors
C1 = 10,000uF - 63V

Semiconductors
D1 = 1N4004
D2 = 1N4004
D3 = 1N4004
Q1 = MJ1504
IC = 7815 REG
BR1 = 1N4004x4

Miscellaneous
B1 = 12 Volt Battery

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Notes:

• Charger's input voltages are 20 volt AC
• R1 and R2 are high wattage resistor like 2W, 3W, 5W and could be above. Select wattage on your choice.
• Q1 and IC requires a good heatsink. If they are mounted on the same heatsink and will throttle the circuit back if Q1 gets too hot.

Get more Battery chargers here:

Simple Trail EA

Simple Trail EA

+------------------------------------------------------------------+
| simple-trail-v1.3 |
| property copyright "Copyright DMW EA Development" |
| |
+------------------------------------------------------------------+

This Expert Adviser  will move the stop loss (S/L) on your MetaTrader 4 terminal up or down depending if the trades are

buy or sell automatically depending on the settings that have been entered.

Purchase this EA here for $ 5.00
Buy this file: simple-trail-v1.3 forex EA

Introduction
------------
This Expert Adviser will move the stop loss (S/L) on your MetaTrader 4 terminal up or down depending if the trades are

buy or sell automatically depending on the settings that have been entered.

Setup
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copy the simple-trail-v1.3.ex4 into C:\Program Files\"your broker"\experts.
restart MT4 to see the EA under experts.

Settings
--------

The following can be configured in the EA:
1. Trail value in pips , if using a 4 digit broker then use a value example 10 for 10 pips , or for a 5

digit broker use a value 100 for 10 pips.

2. Your own comment displayed on the chart.

3. sound - true or false , if true then a tick sound will be heard every time the stop loss is moved.


some helpful info
------------------
don't set the stop loss too low , as the market moves up / down your trade might be closed if the stop loss

is set too low , once you have entered trade give it enough space ( IE stop loss) to reach a profit , I

recommend a minimum of 10 pips.



The EA will also show: the last order that was modified , and current spread.
This Ea will work for 4 or 5 digit brokers.

News Trader

News Trader EA

News Trader is also Pending time EA - they are the same
Have you ever wanted to trade a news event ? , then sat in front of your P.C. waiting for the news to be released only to find that after the news is released the price has moved and its now too late to enter a trade ......

Enter News Trader: a Expert Adviser that you can setup to place pending orders before the news releases , you will almost be guaranteed to enter into a trade even if the price moves up or down.

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You can get FREE FOREX NEWS SIGNALS from the following:

http://www.forexpeacearmy.com/

http://www.newsprofiteer.com/forex-currency-trade-signal.html

http://www.cherryvest.com/lang/en-us/register-for-free-alert/


****************************************************************************************************


With News Trader you will be able to setup:

Watch the setup video
http://www.youtube.com/watch?v=XT4YWWCuj7E

1. next date and time to place pending orders.

2. profit , stop-loss and step.If using a 4 digit broker 10 will equall 10 pips , if using a 5 digit broker
, add a 0 (zero) , so 10 pips will equal 100 , etc.
step is the number of pips above and below the current price that the pending orders will be placed.

3. lot size and expiry time.
expiry time in in seconds , the default is 900 seconds which equalls 15 minutes , check or try with your broker if less than 15 minutes can be used , if pending trades are not placed the expiry time might be too low.

4. your own comment displayed on the chart.

5. number of pending orders to place.Use this in mutiples of 2 , IE 2 or 4 or 6 , etc ...
example: if the setting is 2 it will place 1 buy and 1 sell pending order , if the setting is 4 it will
place 2 buy and 2 sell pending orders , etc ...

6. If during the minute that the EA is active and the market goes crazy up and down and the pending orders are triggered and then closed the EA will automatically open new pending orders according to the number of pending orders set - see point 5.
some helpful info
------------------------

Do not make step to low , 10 pips is about the minimum , you can go higher you risk the orders not being
triggered.
Do not make the take profit to big (dont be gready) , if you are sure the market will make a big move then
set take profit higer.
If you want to manually manage your orders then set the take profit and stop loss to high levels (50 pips)
and close the orders when you like.

The Expert Adviser will also show: number of pending buy / sell stops and total pending orders , and current spread.
This Expert Adviser will work for 4 or 5 digit brokers.

Purchase this EA here for $25.00
Buy this file: Forex Pending time expert advisor , EA

Download the demo version here
http://sites.google.com/site/dmweadev/file-cabinet/pending-time-v1.2.-demo.ex4?attredirects=0&d=1

Lightning surge Protection For Telephone Line

Protect your sensitive electronic equipment connected to your telephone line with this very easy and effective protection circuit. This little circuit has protected my ADSL modem even when lightning has struck the pole my line is connect too!

surge Protection Telephone Line

here is my version of the circuit , I went a bit high on the resistors and used a 90 volt gas discharge tube.
http://www.circuit-finder.com/categories/telephone-related/miscellaneous-telephone/893/protection-for-telephone-line

Circuit diagram:

 

 

 

 

 

 

Description

A long time ago when telephones were so simple almost nothing could go amiss from an electrical point of view, Telecom operators installed surge protection on all telephone lines exposed to storm risks. Paradoxically, now that we are hooking up delicate and expensive equipment such as telephones filled with electronics, fax machines, (A)DSL modems, etc., this protection has disappeared.
However, if you have the good fortune to live in the countryside in a building served by overhead telephone lines, there’s an obvious risk of very high voltages being induced on the lines during thunderstorms. While we have lost count today of all of the modems, fax machines and other telephones that have been destroyed by a ‘bolt of lightning’, surprisingly you only have to invest a few pounds to get a remarkably efficient protection device like the one we are proposing here.
During a storm, often with lightning striking near a telephone line, the line carries transient voltages up to several thousands of volts. Contrary to the HV section of television sets or electrical fences, on which practically no current is running, in the case of lighting striking current surges of thousand of amps are not uncommon. To protect oneself from such destructive pulses, traditional components are not powerful or fast enough.
As you can see on our drawing, a (gas-filled) spark gap should be used. Such a component contains three electrodes, insulated from each other, in an airtight cylinder filled with rare gas. As long as the voltage present between the electrodes is below a certain threshold, the spark gap remains perfectly passive and presents an impedance of several hundreds of MW. On the other hand, when the voltage rises above this threshold, the gas is very rapidly ionized and the spark-gap suddenly becomes a full conductor to the point of being able to absorb colossal currents without being destroyed.
The one we are using here, whose size is of the same magnitude as an ordinary one watt resistor, can absorb a standardized 5,000 amps pulse lasting 8/20 ms! Since we are utilizing a three-electrode spark gap, the voltage between the two wires of the line or between any wire and ground, cannot exceed the sparking voltage, which is about 250 volts here. Such protection could theoretically suffice but we preferred to add a second security device made with a VDR (GeMOV or SiOV depending on the manufacturer), which also limits the voltage between line wires to a maximum of 250 volts.
Even if this value seems high to you, we should remember that all of the authorized telephone equipment, carrying the CE mark must be able to withstand it without damage. This is not always the case however with some low-end devices made in China, but that’s an entirely different problem. Since pulses generated by lightning are very brief, the ground connection of our assembly must be as low-inductance as possible.
It must therefore be short, and composed of heavy-duty wire (1.5 mm2 c.s.a. is the minimum). If not, the coil, composed of the ground connection, blocks the high frequency signal that constitutes the pulse and reduces the assembly’s effectiveness to nothing. Finally, please note that this device obviously has no effect on the low frequency signals of telephones and fax machines and it does not disturb (A)DSL signals either.

Telephone Lightning Protection Products

Joule thief 6 LED Flashlight Torch

I decided to resurrect my 1 AAA cell flashlight torch using the joule thief design .

After reading Evil Mad Scientist Laboratories on how to make a joule thief , I decided to resurrect my 1 AAA cell flashlight torch using the joule thief design .






http://www.evilmadscientist.com/article.php/joulethief















First I made a test rig using a 338 transistor,
6 x 3mm LED's and 11 windings on the toroid.

















Then I compacted the parts ready to fit into the torch.

















Then fit it into the torch,

















The final product















I used this schematic.

Single AA flashlights

Trendnet ADSL modem router gets hot

 ADSL modem router gets hot

As we all know , heat is the the no.1 enemy of electronic components. After having 2 Trendnet units I find that they get pretty hot after some time , so this time I decided to cool this one down without voiding the warranty. As can be seem from the pictures , take 2 "smallish" fans , stip out all the parts of the middle one , glue the 2 together so that the outer fan blows air in , use a piece of thick plastic as the base and attach it the the bottom of the unit with double sided tape , close the open hole on the gutted fan that is closest to the modem , wire up a small power supply , I'm using a old Nokia phone charger at 10 volts. the unit now runs cool to the touch as it used to run "hot" on the outside , so it must have really been hot on the inside. This should extend the life of the unit by a much longer time.