hi for all members.

no comment :roll:

Attached Thumbnails

 

 

hi hsab,
what does it do..?

 

hi

this sheme works with 12v batteries

we can use it at home when light cut off; in vehicule to repair wheel inthe dark far way home........................

i build it and it works ok .

by

 

what does this circut draw from the power suply (i.e. car battery)?
and how powerful can the fluorescent be?

 

hi

use 12 v batteries

power lamp fluo from 18watts to 36 watts

@+

 

this is nice[/i][/b]

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satish kikani

 

Hello,
how are u doing today?iam stanley from Nigeria.iam a student,i need ur help.I was told in school to present a project topic for my final year.I need ur help ok.
my email address is stanleycarl2@yahoo.com
i will like us to communicate via my email address cos i have time checking it everyday.
thankz
stanley

 

Hi hsab:

hope you're having a nice day today.

We had a similar project way back in my college days. Just want to ask if the it's possible to use a 1/2-inch (12.5mm) diameter AM radio antenna ferrite rod instead of the "philips tv psu ferrite" used in this project ?

By the way, I'm from the Philippines, so i have to find the JIS (Japanese) equivalents of BC series transistors. That I can google my way from here.

jun balista [etes_oroq]

 

Why did your lights get cut off? Did you forget to pay your electricity bill?

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Uncle $crooge

 

This is OLD technology, it is much more efficient to use the battery power to drive LED's directly. If I remember correctly, white high efficiency LED's produce around 130 lumen per watt versus about 80 for fluorescents.

 

Flourescent are more efficient than LEDs, well for producing white light anyway.

The problem with this circuit it it drives the tube of pulsed DC not AC so it won't be as birght and it won't last as long. You need a push-pull driver and centre tapped transformer primary to get an AC output and drive the lamp properly.

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I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

Found this one haven't tried it yet, I am in the proces of building it.

 

http://www.electro-tech-online.com/156617-post7.html

That isn't a very good way of doing this, please refer to my post linked above.

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I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

The output of the transformer shown is still AC! However that type of drive is indeed inefficient and makes poor use of the magnetic core. The output may be a bit "spikey" too.

Rolf, what Hero999 says is accurate- good flourescents are more efficient than LEDs.

Starting and driving a flourescent is a bit tricky, and requirements vary from tube to tube. Of particular interest is that the impedance of the tube changes as it ages or just warms up. A fixed voltage may either not be enough to drive the tube with enough current OR it will provide the tube with too much current. I'm not big on home-grown solutions myself because it's such a complicated task to do right.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

 

I believe we've seen this discussion on this forum before. The transformer's primary is driven by one transistor connected to a positive supply. When the transistor shuts off the back-emf generate by the field around the primary collapsing induces a large negitive pulse in the secondary, this repeates continiously. Hence it is generating pulsed DC not AC. The pulses travel in one direction only, from the cathode to the anode causing the catode to be brighter and excess electrode sputter around it, this isn't good. One solution to this problem is to simply add a capacitor in series with the tube, this will effectively block the DC level (remember pulsed DC is simply an AC voltage plus half it's peak value DC offset).

True, because the pulses are only one polarity the same is true for the field, in effect only half the magnetising potential of the core is being used.

That's an understatement, there's a heave peek at the start of each pulse followed by ringing (which may be damped when the tube ignites).

To date this is correct, but while fluorescent tube technology is mature LEDs are continuing to improve, it's only a matter of time before they beat fluorescents.

It starts off open circuit before ignition and drops one struck, then continiues to drop as the current increases until either there's no more gas to ionise or the wiring resistance or fuse limits the current.

A constant current source is idea but this is normally approximated by a large inductor, at mains frequencies, or with a high frequency inverter a capacitor can be used (which will also solve the pulsed DC problem). Often the transformer is specially designed to have a very high leakage inductance to limit the current, this is true bot for some mains ballasts and inverters.

__________________

I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.