Need of psu schematic that can give 120vdc

Thread Starter

Dzoro

Joined Feb 1, 2019
161
Hey guys i need some crude but functional psu that can give a 120vdc and about 200 mA of current.
I need this power supply beacose i have 3 led strips that are conected in series.Each one of them uses about 40v and around 50mA,so 3×40 is 120v.
I was thinking about a voltage doubler but i don't know if it is eficient enough.
The second idea i had to mind is to rectify 220 v ac with full bridge rectifier and somo filter capacitor and when the ac is converted i will get around 320 v dc.So i wanted to put a voltage devider beacose i don't need much current.And with that devider to stepdown the voltage to 120v dc .
Please help and guide me i will apreciate it
 

sghioto

Joined Dec 31, 2017
1,562
Dzoro welcome to AAC.
Actually three strips in series will only need 50ma at 120 vdc. If you parallel the strips you only need 40 volts at 150ma.
150ma is not a lot of current. There are inexpensive LED supplies that should work with your setup.
SG
 

Wendy

Joined Mar 24, 2008
22,181
I am willing to help. but first the TS needs to understand this is a potentially lethal mix of voltages and current One minor mistake and you die a very painful death, It is why AAC does not allow LEDs to mains discussions(which is done commercially all the time.) We also don't like making DC voltage from the wall socket which has some hidden death traps associated with it. I like mentoring people new to electronics, which is one reason they made me a moderator around here. The pay sucks (a joke as we are all volunteers here). For future reference if you type @Wendy in a post I will be tagged to read it. How do I know you are new to electronics? It comes with the nature of the question, an experienced hand would already know how to do this, as it is actually pretty easy. Your IP address says you are in Macedonia, I have no clue what line voltages are there. What kind of access to components do you have? How much are you willing to spend? I also assume English is not your mother tongue? The latter does not matter as this is an international site.
 
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Thread Starter

Dzoro

Joined Feb 1, 2019
161
I am willing to help. but first the TS needs to understand this is a potentially lethal mix of voltages and current One minor mistake and you die a very painful death, It is why AAC does not allow LEDs to mains discussions(which is done commercially all the time.) We also don't like making DC voltage from the wall socket which has some hidden death traps associated with it. I like mentoring people new to electronics, which is one reason they made me a moderator around here. The pay sucks (a joke as we are all volunteers here. For future reference if you type @Wendy in a post I will be tagged to read it. How do I know you are new to electronics? It comes with the nature of the question, an experienced hand would already know how to do this, as it is actually pretty easy. Your IP adress says you are in Macadonia, I have no clue what line voltages are there. What kind of access to component do you have? Hoe much are you willing to spend? I also assume English is not your mother tongue? The latter does not matter as this is an international site.
I have a lot of components to work .
I work with electronic 4 years but not every day,i am kind of a hobyst,i am into robots and audio aplifiers so thats why i do not know how to make this hv psu beacose i never built an one whit such a high voltage.
I have european sockets so i have 220 v ac
I have an idea how to make the psu like a boost converter with 555 timer or some pwm generator.I have some ic's but i don't know the part name.
Is this a good idea to make boost converter

Dzoro welcome to AAC.
Actually three strips in series will only need 50ma at 120 vdc. If you parallel the strips you only need 40 volts at 150ma.
150ma is not a lot of current. There are inexpensive LED supplies that should work with your setup.
SG
Yes i know that but the leds are conected in series fabricly so i don't want to make my ajustment,they also have a conector.I like to keep thing original.
Thanks for the reply

A LEDs directly connected go the mains solution which is probibited by the site's User Agreement has been removed.
I kow that so thats why i asked the question to give me somo ideas that work but are not too dangerous
 
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Wendy

Joined Mar 24, 2008
22,181
The easy way is to buy an AC inverter, or make one from the ground up, In the later case You cou make the DC level variable and tweak it to whatever value you want.

Wendy's Index
AC/DC Inverters

I will restate what I said, a minor mistake could be you last with this project, so be very, very careful making it. It is why we don't allow discussion on certain subjects. We have had young users ( I assume he was a child who wanted to electrify a doorbell with 220VAC for a laugh, that thread was promptly closed.
 

Thread Starter

Dzoro

Joined Feb 1, 2019
161
The easy way is to buy an AC inverter, or make one from the ground up, In the later case You cou make the DC level variable and tweak it to whatever value you want.

Wendy's Index
AC/DC Inverters

I will restate what I said, a minor mistake could be you last with this project, so be very, very careful making it.
When i open the link the page says 404
The easy way is to buy an AC inverter, or make one from the ground up, In the later case You cou make the DC level variable and tweak it to whatever value you want.

Wendy's Index
AC/DC Inverters

I will restate what I said, a minor mistake could be you last with this project, so be very, very careful making it. It is why we don't allow discussion on certain subjects. We have had young users ( I assume he was a child whowanted to electrify a doorbell with 220VAC for a laugh, that thread was promptly closed.
When i open the link it says 404 not found.
Any solutions?
 

sghioto

Joined Dec 31, 2017
1,562
Yes i know that but the leds are connected in series fabricly so i don't want to make my adjustment, they also have a connector. I like to keep thing original.
This sounds like the led strip is something commercial. If so, don't they sell a power supply to go with it?
SG
 

Thread Starter

Dzoro

Joined Feb 1, 2019
161
A 120V to 6.3V 200 VA or better. I will remove the broken link Use Figure 2 instead.
This transformer is going to be the voltage source for the circuit if i am not mistaken?

This sounds like the led strip is something commercial. If so, don't they sell a power supply to go with it?
SG
It has its own psu.Actualy it is an inverter that gives about 120 volts but its broken and i dont vant to give 10 bucks for that thing so thats why i asked the question
 
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AnalogKid

Joined Aug 1, 2013
8,705
Nothing you can build yourself will cost less than 10 bucks. I'm not trying to discourage you; it will be more fun and more rewarding, but also more money. Even if you already own a suitable small power transformer, the cost will be close.

ak
 

Thread Starter

Dzoro

Joined Feb 1, 2019
161
Nothing you can build yourself will cost less than 10 bucks. I'm not trying to discourage you; it will be more fun and more rewarding, but also more money. Even if you already own a suitable small power transformer, the cost will be close.

ak
I have a lot of components to work with
 

Wendy

Joined Mar 24, 2008
22,181
The transformer will be used to boot the AC voltage to high voltage AC, at which point we rectify it and filter it. We will need a variable power supply to set the output voltage. I am a little slow today due to a fever. I have fixed the broken links you found.
 

Thread Starter

Dzoro

Joined Feb 1, 2019
161
Thankyou
The transformer will be used to boot the AC voltage to high voltage AC, at which point we rectify it and filter it. We will need a variable power supply to set the output voltage. I am a little slow today due to a fever. I have fixed the broken links you found.
But i found the problem with the inverter that came with the led strips.
The smd fuse was blown and i change it and now the led strips work perfectly,but thankyou for all the replays you are the best
 

MisterBill2

Joined Jan 23, 2018
7,325
Get a small 24 volt transformer and then build a voltage double circuit, and then use a resistor to limit the current. Safe, cheap, and fairly easy.use a separate resistor for each strip so that if one fails open the others will still be OK. AND it will be cheaper than the capacitors for that across the line circuit besides being safe, and much less of a fire hazard.

Also, "Hi Wendy"
 

Thread Starter

Dzoro

Joined Feb 1, 2019
161
Get a small 24 volt transformer and then build a voltage double circuit, and then use a resistor to limit the current. Safe, cheap, and fairly easy.use a separate resistor for each strip so that if one fails open the others will still be OK. AND it will be cheaper than the capacitors for that across the line circuit besides being safe, and much less of a fire hazard.

Also, "Hi Wendy"
I wanted to do that but i fixed the inverter that came with the led strips or the led driver i don't know how is called and now the led strip work,but thanks for the replay.
 

MisterBill2

Joined Jan 23, 2018
7,325
I wanted to do that but i fixed the inverter that came with the led strips or the led driver i don't know how is called and now the led strip work,but thanks for the replay.
Quite welcome indeed. and keep in mind that direct line connections can be dangerous, not only for the shock hazard aspect, but also because there is a lot of power available from the mains during a fault, much more than you can imagine, until the circuit protection device disconnects the power. Until that 15 amp fuse clears your fault current is limited only by the resistance of the wiring..
 
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