Author Topic: Prove me wrong (solved)( voltage doubler, redundant diodes)  (Read 1735 times)

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Offline RajTopic starter

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Prove me wrong (solved)( voltage doubler, redundant diodes)
« on: November 12, 2019, 04:25:20 pm »
I'm there commentator, 'Suraj Grewal' in this video.
Prove the statement in the screenshot is working for schematic in that point of video.

Video link-https://youtu.be/Rmq4OKhKX-4

My statement... There will never be current flow across diode d3,d4
« Last Edit: November 15, 2019, 08:53:05 am by Raj »
 

Offline RajTopic starter

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Re: Prove me wrong
« Reply #1 on: November 12, 2019, 04:35:11 pm »
Extra protection for capacitor?
 

Offline RajTopic starter

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Re: Prove me wrong
« Reply #2 on: November 12, 2019, 04:47:10 pm »
redrawn for clearity
 

Offline AVGresponding

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Re: Prove me wrong
« Reply #3 on: November 12, 2019, 04:47:30 pm »
This circuit is a bit of a mule, a hybrid of dual rail centre tapped half wave and single rail full bridge. Is it a single rail full bridge with a bodge to get a dual rail supply?
nuqDaq yuch Dapol?
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Offline Yansi

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Re: Prove me wrong
« Reply #4 on: November 12, 2019, 04:52:36 pm »
Just a damn classic voltage doubler with two useless diodes.
 

Offline RajTopic starter

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Re: Prove me wrong
« Reply #5 on: November 12, 2019, 04:55:44 pm »
Just a damn classic voltage doubler with two useless diodes.
Maybe he did that on purpose, so that it becomes more memorable.
 

Offline JackJones

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Re: Prove me wrong
« Reply #6 on: November 12, 2019, 05:14:28 pm »
Sometimes this circuit is used for products that work with both 120VAC and 240VAC.

Drawn like this it would double the output voltage, but when you break the link between TP+ and AC- it would act as a full bridge rectifier for 240V (or 230V really) countries. Although for use with 230V there should be resistors across both the caps to balance out the leakage current.

That might be where the mistake comes from, it's not an uncommon thing to see in various products as I understand it.
« Last Edit: November 12, 2019, 05:16:22 pm by JackJones »
 
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Offline RajTopic starter

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Re: Prove me wrong
« Reply #7 on: November 12, 2019, 05:20:41 pm »
Sometimes this circuit is used for products that work with both 120VAC and 240VAC.

Drawn like this it would double the output voltage, but when you break the link between TP+ and AC- it would act as a full bridge rectifier for 240V (or 230V really) countries. Although for use with 230V there should be resistors across both the caps to balance out the leakage current.

That might be where the mistake comes from, it's not an uncommon thing to see in various products as I understand it.

Bingo....ive seen that in many smps power supply input side...would have made more sense if he was to put a switch there.
 

Offline schmitt trigger

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Re: Prove me wrong
« Reply #8 on: November 12, 2019, 05:35:51 pm »
This circuit (with a switch as mentioned above) was used for many years in the "silver box" PC supplies.

The switch would modify the circuit as a voltage doubler (for 120VAC) or a full bridge (for 240 VAC).
 
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Offline soldar

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Re: Prove me wrong
« Reply #9 on: November 13, 2019, 11:06:52 am »
I'm there commentator, 'Suraj Grewal' in this video.
Prove the statement in the screenshot is working for schematic in that point of video.

Video link-https://youtu.be/Rmq4OKhKX-4

My statement... There will never be current flow across diode d3,d4

Please use descriptive titles in your threads.
All my posts are made with 100% recycled electrons and bare traces of grey matter.
 
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Offline RajTopic starter

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Re: Prove me wrong
« Reply #10 on: November 14, 2019, 10:01:07 am »
I'm there commentator, 'Suraj Grewal' in this video.
Prove the statement in the screenshot is working for schematic in that point of video.

Video link-https://youtu.be/Rmq4OKhKX-4

My statement... There will never be current flow across diode d3,d4

Please use descriptive titles in your threads.

Apparently I can still modify it... Suggest one.
 

Offline Gyro

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Re: Prove me wrong (solved)
« Reply #11 on: November 14, 2019, 10:09:57 am »
Voltage doubler, redundant diodes?
Best Regards, Chris
 


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