# Pulse transformer

Discussion in 'General Electronics Discussion' started by Sravanthi, Jul 9, 2015.

1. ### Sravanthi

72
1
Feb 4, 2015
HI...

How we can calculate the minimum coil current required to the pulse transformer from the datasheet specifications.

In datasheet thy have given ignition current value. Does this value is the minimum current for the coil.
Thank you...

2. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,397
2,777
Jan 21, 2010
perhaps you can post a link to the dataset so we're ask talking about the same thing.

72
1
Feb 4, 2015
4. ### davennModerator

13,596
1,875
Sep 5, 2009
no, it says UP TO = up to a max of xxxx Amps varies with the model

5. ### Sravanthi

72
1
Feb 4, 2015
Then what is the minimum amount required?

6. ### davennModerator

13,596
1,875
Sep 5, 2009
The ignition current is the output current
they have models that have output currents ranging from 0.1A to 3A

it says nothing of the input current ... well not that I can see

7. ### Sravanthi

72
1
Feb 4, 2015
Hi,,,
I am using IT237 model
http://schaffner.com/en/products/da...transformer-with-single-secondary-winding.pdf

For this I am driving the pulses from 555 timer of datasheet(http://www.ti.com/lit/ds/symlink/ne555.pdf).

I designed astable multivibrator with ON duration of 0.05ms and 0.150ms OFF duration with 5V.
But when I am trying to drive this pulse to pulse transformer this pulse at input side and output side its having ON duration of 0.05ms and OFF duration as 0.7ms.
Can i know the reason for this.
I am having doubt that whether 555 timer can drive the pulse transformer current.
Or is there any reason for this.

For your reference here I am attaching the images.
First image is multivibrator output before feeding to the Pulse transformer. Second image is pulse transfomer input(multivibrator output) and pulse transformer output.

File size:
68.3 KB
Views:
57
File size:
73.6 KB
Views:
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8. ### Sravanthi

72
1
Feb 4, 2015
Hi,,,
I am using Pulse transformer IT237 model
http://schaffner.com/en/products/da...transformer-with-single-secondary-winding.pdf

For this I am driving the pulses from 555 timer of datasheet(http://www.ti.com/lit/ds/symlink/ne555.pdf).

I designed astable multivibrator with ON duration of 0.05ms and 0.150ms OFF duration with 5V.
But when I am trying to drive this pulse to pulse transformer this pulse at input side and output side its having ON duration of 0.05ms and OFF duration as 0.7ms.
Can i know the reason for this.
I am having doubt that whether 555 timer can drive the pulse transformer current.
Or is there any reason for this.

For your reference here I am attaching the images.
First image is multivibrator output before feeding to the Pulse transformer. Second image is pulse transfomer input(multivibrator output) and pulse transformer output.

File size:
68.3 KB
Views:
57
File size:
73.6 KB
Views:
71
9. ### Colin Mitchell

1,417
312
Aug 31, 2014
It looks like the transformer is upsetting the frequency (waveform) produced by the 555. Try separating the two with a buffer transistor and separate power supplies.
The transformer DC resistance is far too low for the 555.

Last edited: Jul 16, 2015
10. ### Sravanthi

72
1
Feb 4, 2015
Is there any other way than driving through transistor.
Is there any 555 timer which drives higher currents.

11. ### Colin Mitchell

1,417
312
Aug 31, 2014
It's a shit of a chip.
The worst chip ever designed.

Arouse1973 likes this.
12. ### Sravanthi

72
1
Feb 4, 2015
Is there any other pulse transformer for these requirement???

13. ### Martaine2005

2,827
754
May 12, 2015
I couldn't disagree with you more!
This versatile little 8 pin chip has opened the electronics door for many a tinkerer like me and others.
But that's just my opinion.

Martin

Supercap2F likes this.
14. ### Colin Mitchell

1,417
312
Aug 31, 2014
"I couldn't disagree with you more!"

Let me just inform you of the truth of the matter.
Just because there has been 30 billion chips sold and thousands of circuits, don't mean it is not the worst chip ever designed.
For a start, the mere fact that there has been a number of attempts to improve the features by bringing out different versions, is proof of its short-comings.
For a start, the chip takes about 10mA when sitting around doing nothing.
Secondly, the chip cannot be turned off.
Thirdly, the chip does not drive rail-to-rail and
Fourthly, it goes hay-wire when driving a low impedance load and the "engineer" does not know why.
I realise it is old technology, but to use 28 transistors to perform such a simple task, needs to be looked at.
I am absolutely amazed that no other company copied or brought out an improvement.
It goes to show that no other company really had any competent engineers to analyse the situation.
In fact all our chips are very poorly designed and were the product of a handful of engineers.
All the original 7400 and CD4000 chips were very poorly designed with a double row of pins.
This should have been a single row to make PCBs smaller and designing much easier.
And to have 4 of the same gate on each chip is a stupid idea.
Fortunately the microprocessor and microcontroller came out and made all these chips redundant.
But you look back and see how nothing was changed for 30 years.

Arouse1973 likes this.
15. ### Martaine2005

2,827
754
May 12, 2015
That implies that it is indeed a very popular chip.

I don't see any short comings! I see a successful chip that has sold billions.
Every item bought from yester year to today have different versions. It's called 'updating' and 'improving'.
The cmos version if proof of that.

I could go on and on, but it's futile if you walk around blind folded.
Times change, ideas change and technology too.
You just proved that..You said "fortunately the μcontroller came", well, for us tinkerers who have no interest in programming, the 555 and 4017 are just a couple of very popular chips for the hobbyist.

I also think that with your level of experience, you could design a better chip because you know all their faults.
Should be really easy for you. I will watch this space.

Martin

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16. ### AnalogKid

2,370
661
Jun 10, 2015
I've been reading your posts for a while now, often wondering the same thing. Your command of semiconductor history is very interesting. How old are you?

ak

5,164
1,081
Dec 18, 2013
At last I have found a use for the 555 timer

Martaine2005 likes this.
18. ### Martaine2005

2,827
754
May 12, 2015
I knew you wouldn't be able to stop yourself chipping in. They sell them a lot smaller now.

Arouse1973 likes this.
19. ### AnalogKid

2,370
661
Jun 10, 2015
Colin. I was responding to his post. I should have trimmed more.

ak

20. ### Martaine2005

2,827
754
May 12, 2015
Colin is a good engineer, but doesn't like the 555
He has/had a website for beginners like me called Talking Electronics.

Very informative and great little circuits.

Martin