|
Can I build a power supply?
I am relatively new to ham radio. I am wanting to build a base station
in my bonus room and use some mobile radios up there. Is it feasible to build my own power supply? I know one radio requires 13.8 volts and a minimum of 12 amps. I would like to use more than one radio though. What about buying one of those cheap emergency jump start pwer cells you can keep in your car. Could I just use one of those and keep it plugged into the wall charging at all times? I like the idea of building one but not sure if it would cost more that way or not. What would I need to build one besides a transformer and rectifier? |
|
I would buy one instead of building it.It would be cheaper.
Jacques |
John Miller writes:
wrote: I am relatively new to ham radio. I am wanting to build a base station in my bonus room and use some mobile radios up there. snip I like the idea of building one but not sure if it would cost more that way or not. What would I need to build one besides a transformer and rectifier? Welcome to the ranks; an excellent reference is the ARRL handbook. Your local library should have a copy or copies. Quick answer to your question: in addition to transformer and rectifier, you'll need a safe enclosure, overload protection, voltage regulation and filtering. These days, though, it will probably cost you more to build one, unless you have a well-stocked junk box. Didn't used to be that way. Alternatives: PC power supply (you may need a load on the +5 VDC line for the +12 VDC to be properly regulated) and eBay (always many good power supplies available). Building one is certainly an option and a good education experience which may outweigh the additional cost and effort. But, maybe not best as a first project, mainly due to the need for high current regulation but still not out of the question. --- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/ Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/ +Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm | Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html Note: These links are hopefully temporary until we can sort out the excessive traffic on Repairfaq.org. Important: Anything sent to the email address in the message header above is ignored unless my full name is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. -- John Miller email address: domain, n4vu.com; username, jsm Surplus (FSoT): New Conn V1 double trumpet case, no logo Tektronix 465B oscilloscope New leather business case |
I can get a rectofier at radio shack for 5 bucks. I can build the
enclosure out of steel and weld it togther myself. I need soemone to explain how the circuitry works for a newbie like me. For instances, what does a transformer do? I mean why couldnt you just wire directly into the rectofier? Could I use a household dimmer switch to adjust the amperage? Could I just use one of those jump start things with a battery inside them and leave it plugged up? Then it would even work with the power going out, right? |
wrote in message oups.com... I can get a rectofier at radio shack for 5 bucks. I can build the enclosure out of steel and weld it togther myself. That's only the beginning... I need soemone to explain how the circuitry works for a newbie like me. For instances, what does a transformer do? I mean why couldnt you just wire directly into the rectofier? Don't even think about doing that, do you want a 12v DC power supply or a 170v DC power supply? Could I use a household dimmer switch to adjust the amperage? No, dimmer switches don't adjust amperage, and even if they did that's not what you need to do. Could I just use one of those jump start things with a battery inside them and leave it plugged up? Then it would even work with the power going out, right? Perhaps, but I'm not sure how long the battery would last, they're really designed for intermittent use. You've got a lot of homework to do before you attempt to build a power supply, all the information you seek is readily available online. Unless you can find an old car battery charger to salvage one from, the transformer will be the most expensive part by far. I would just use an old PC power supply personally. |
|
wrote in message ups.com... | I am relatively new to ham radio. I am wanting to build a base station | in my bonus room and use some mobile radios up there. | | Is it feasible to build my own power supply? I know one radio requires | 13.8 volts and a minimum of 12 amps. I would like to use more than one | radio though. | | What about buying one of those cheap emergency jump start pwer cells | you can keep in your car. Could I just use one of those and keep it | plugged into the wall charging at all times? | | I like the idea of building one but not sure if it would cost more that | way or not. What would I need to build one besides a transformer and | rectifier? Ham radio or CB radio? Which license do you have? A Google for "build your own power supply" got 155 hits. N |
You did say that you are a New Ham..Best do a bit of reading
If you dont you some will be an SK. kip |
Somewhere between the AC input and DC output must be an
transformer. This is essential to human safety. Radio Shack often sells paperbacks that explain how this is built. You need to read these books with schematics, part numbers, and cautions - such as the needed transformer. Way too much to explain here. But those books make quick reading. Power supplies in kit form are so simple. But first you need to read - to learn about the simple mistakes that can kill. wrote: I can get a rectofier at radio shack for 5 bucks. I can build the enclosure out of steel and weld it togther myself. I need soemone to explain how the circuitry works for a newbie like me. For instances, what does a transformer do? I mean why couldnt you just wire directly into the rectofier? Could I use a household dimmer switch to adjust the amperage? Could I just use one of those jump start things with a battery inside them and leave it plugged up? Then it would even work with the power going out, right? |
I can get a rectofier at radio shack for 5 bucks. I can build the
enclosure out of steel and weld it togther myself. I need soemone to explain how the circuitry works for a newbie like me. For instances, what does a transformer do? I mean why couldnt you just wire directly into the rectofier? Stryped- You certainly have the right attitude. Yes, all the answers can be found here or elsewhere on the web, but there is also a lot of misinformation along with the warnings about killing yourself! The best suggestion so far, has been to look for a copy of the ARRL Handbook. Your local library should have other resources as well. You should be aware that rectified DC across the filter capacitor may be close to one and a half times the transformer's AC voltage. If you don't understand this, then you need to look it up in the Handbook. The suggestion to modify a computer power supply may be a good one. I recall seeing an article on how to do that, but don't remember where. You might search for it with Google. As a learning experience, you might try a simple power supply with no regulator. If you could obtain a transformer that would supply the right voltage at sufficiently high current, you could rectify it and filter the DC with a large computer-type capacitor. If the output voltage doesn't exceed about 14 volts DC with nothing connected to it, there might still be about 12 volts under load. If not, then try a bigger capacitor! 73, Fred, K4DII |
| All times are GMT +1. The time now is 10:59 PM. |
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter