Greetings! I am a new member and decided to design a fun new project. The issue I am having is input voltage. My idea is this:
Using a household outlet will yield 120V AC. I figured that I can make a diode bridge to convert it to 120V DC. Now, My design will use a maximum of 60V which will be variable through the use of a potentiometer. The 60V will split off into 2 or 3 more mini circuits, still prototyping various ideas on that. My questions are this:
1.) What type of diodes should I use for the diode bridge to make sure nothing burns?
2.) What kind of voltage module can I use? If one exists, if not, how can I go about building one?
3.) Are hot diodes or resistors capable of melting acrylic?
P.S. The project will be a secret until it is completed :whistle:
Direct conversion of household AC to DC as you propose is extremely dangerous, and it is clear from your question that you do not understand the problems. Don’t even attempt to do this. Instead, buy a power supply that provides what your project requires.
I’m with these guys, please don’t mess with AC. If you don’t know, then you shouldn’t even be considering it. Plus, I don’t know of anything that will need 60VDC. And to use just a pot so you can make it variable, that’s not going to work…
Let us know why you think you need 60V. Or you can tell us what you want done and/or what devices you need and we can tell you what supply you need.
Like Mac said, if you want to keep this project a secret, you are just going to end up hurting yourself, burning down the house and/or hurting someone else.
I am trying to run an experiment using silver rods. I would like to use a potentiometer to vary the amount of electricity going through the silver rods. I currently have a setup of 5 9V batteries in series to achieve 45v. I was thinking of designing my circuit around a household outlet so that I would not need to worry about batteries and in turn be able to achieve higher voltage.
If you look around, you can get power supplies very cheaply. Here is a 48 volt, 0.38 ampere brick for only $5.50 plus shipping. http://www.allelectronics.com/make-a-st … ply/1.html Or find them at a thrift store for even less. Much safer than fooling with the house AC and they sure beat 9V batteries!
If you plan to do a lot of this and really need the variable voltage, spend a bit more to get a nice variable voltage bench supply. It should last for many years and be more useful than you can imagine – in an emergency I’ve even used them to (slowly) recharge car batteries http://www.mpja.com/Benchtop-Power-Supplies/products/2/
jremington:
If you look around, you can get power supplies very cheaply. Here is a 48 volt, 0.38 ampere brick for only $5.50 plus shipping. http://www.allelectronics.com/make-a-st … ply/1.html Or find them at a thrift store for even less. Much safer than fooling with the house AC and they sure beat 9V batteries!
If you plan to do a lot of this and really need the variable voltage, spend a bit more to get a nice variable voltage bench supply. It should last for many years and be more useful than you can imagine – in an emergency I’ve even used them to (slowly) recharge car batteries http://www.mpja.com/Benchtop-Power-Supplies/products/2/
Wow, I did not realize that power bricks were able to have voltage limits that high, I rarely saw any of them go above 12V. I do have a variable power supply I use for low voltage projects and tests, I use a Tekpower HY-1502. It is capable of 15V max @ 2 amps. My inexperience and lack of knowledge is mainly in the AC field, something I should definitely brush up on. I am now wondering if it would be wise to take apart the power supply brick and seat it into the enclosure and solder the power connections onto the PBP board and split the incoming 48V to various potentiometers in various sub circuits. I am a bit familiar with how hot power bricks get so I would think of adding 1 120mm PC fan as an intake to keep the enclosure cool and another 120mm fan as an exhaust. Sound solid?
What makes you think you need such high voltages ? If you’re trying to achieve some desired current through your silver rods and you’re basing this upon a stack of 9V batteries, then you may be mislead. 9V batteries have a limited current output, perhaps 200 mA, before they drop severely in output voltage.
Buy an isolation transformer and a Variac to feed the diode bridge. The isolation transformer keeps you moderately safe. The Variac will allow you to vary the AC voltage from 0 to 110% of your line voltage. You can use 1N5408 diodes to make a bridge. You’ll need a high voltage (more than 250V) capacitor and a bleeder. Note this will be unregulated and the current will only be limited by the transformer and Variac (and the circuit breaker in your house!).
Mee_n_Mac:
What makes you think you need such high voltages ? If you’re trying to achieve some desired current through your silver rods and you’re basing this upon a stack of 9V batteries, then you may be mislead. 9V batteries have a limited current output, perhaps 200 mA, before they drop severely in output voltage.
Well I have 5 9v batteries stacked in series and I do achieve results. I just want to experiment and see what results I can achieve if I up the voltage.
Go for one of those variable powersupplies that Jremmington sugested. There is one upto 120 volt, 1 amp if you need to experiment. (the 60 volt types would be borderline for the range of your experiment) With those you can be reasonable sure that the current and voltage is limited, to whatever you desire or feel neccesary. (start low) And does not blow a circuitbreaker in your home if you short it across conducting metal. Because if you use mains 120 volt there is a tremendous amount of uncontrolled power available. Shorting it across silver bars is going to create fireworks. Not unlike welding.
Valen:
Go for one of those variable powersupplies that Jremmington sugested. There is one upto 120 volt, 1 amp if you need to experiment. (the 60 volt types would be borderline for the range of your experiment) With those you can be reasonable sure that the current and voltage is limited, to whatever you desire or feel neccesary. (start low) And does not blow a circuitbreaker in your home if you short it across conducting metal. Because if you use mains 120 volt there is a tremendous amount of uncontrolled power available. Shorting it across silver bars is going to create fireworks. Not unlike welding.
A 120V would be handy but 60 Volts is max of what I would need but I would also need to know how it would react if I added a DPDT toggle switch to reverse polarity on the fly.
Well, I’m sure there is a way to use a switch topology to redirect the current through the silver bar with minimal or no parts. Just make sure the switch is up to spec also. The inductance of the wires and what not may cause spiking anyway.
You’re starting to make me curious what you are trying to investigate. Current running through silver rods can’t be that special, can it?
