Life is full of changes, and this last year has been a doozy! After wrestling with the decision for months, I've realized that I just can't continue to spend the time that "glitchbuster.com" requires. I have truly enjoyed the relationships with so many of you, and I sincerely appreciate your business as well as your patience - particularly at times this last year when my promptness left much to be desired.
I'll be selling off my inventory, and must wrap it up very soon so I can focus on the upcoming semester (I teach electronics full-time at our local community college). Anything left in significant quantity at that point may appear on eBay some day.
I'll be monitoring sales of each item and reducing prices if needed to move it out. On the other hand, there is not much left of many items so don't delay if you see things you are interested in. Listings will just "disappear" as I get low on each item (as some of you have already noticed over the last few days). For example, LM317T, 16F628, 16F648A, IRL520, and more, are already gone. Many others are getting very close. Up until the last day or two I thought I'd be ordering more of those parts, and I apologize to anyone who may have been waiting for them to arrive. This has been a very difficult decision - I have really enjoyed doing this!
If you are interested in a larger quantity of an item, send me an email and I'll do my best to make you a very friendly deal.
I've never had a minimum order charge, mostly to help spread the word about glitchbuster. Now that that's no longer an issue, I need to add $1 to any order under $14 before shipping to make it (sort of) worth taking the time to process. At these prices, I don't think you'll have any trouble finding at least $14 worth of goodies - but if not, the shipping/handling to US addresses will be $2.95. And, going the other direction, shipping is FREE on orders over $70 in the US. The normal $1.95 shipping in the US still applies for orders from $14 to $70.
I also have a number of new Microchip programmers, lab boards, etc, such as ICD-2, PicStart Plus programmers, etc. All brand new in the factory packaging. I'm planning to offer them on eBay, but email if you would like first shot at them.
I will still be "around" to handle any customer service issues that may come up. Who knows... maybe I'll actually have time for an occasional project, instead of just enjoying hearing about yours. :o) I'd like to finally add some projects and info to this website - it won't just disappear after the inventory is gone. Based on the questions I frequently receive, there still seems to be a need for information about using certain devices - including the newer PICs. I've always wanted to add info articles to the website, and now maybe I'll have time to do it.
Thank you very much,Randy Jones, KE7DRRrandy@glitchbuster.comReno/Tahoe, Nevada USA (...At the north end of the Ponderosa, if you've ever seen that burning map at the beginning or end of those old Bonanza westerns. Virginia City, Lake Tahoe, Reno, and Carson City are all just a short "ride" from here.)
PS - IMPORTANT EMAIL NOTE: You may notice that my replies to your email sometimes use odd wording... This is because I'm doing my best to avoid having my email to you "disappear" into spam filters. Things like "free shipping" etc. are very bad, and even short, simple messages discussing details of a transaction have often been relegated to "spam" status. If you don't receive my email please check your spam/junk folder or email me again to let me know that you didn't receive it. I'll then do everything possible to send you a reply that makes it "under the radar.
I'll be selling off my inventory, and must wrap it up very soon so I can focus on the upcoming semester (I teach electronics full-time at our local community college). Anything left in significant quantity at that point may appear on eBay some day.
I'll be monitoring sales of each item and reducing prices if needed to move it out. On the other hand, there is not much left of many items so don't delay if you see things you are interested in. Listings will just "disappear" as I get low on each item (as some of you have already noticed over the last few days). For example, LM317T, 16F628, 16F648A, IRL520, and more, are already gone. Many others are getting very close. Up until the last day or two I thought I'd be ordering more of those parts, and I apologize to anyone who may have been waiting for them to arrive. This has been a very difficult decision - I have really enjoyed doing this!
If you are interested in a larger quantity of an item, send me an email and I'll do my best to make you a very friendly deal.
I've never had a minimum order charge, mostly to help spread the word about glitchbuster. Now that that's no longer an issue, I need to add $1 to any order under $14 before shipping to make it (sort of) worth taking the time to process. At these prices, I don't think you'll have any trouble finding at least $14 worth of goodies - but if not, the shipping/handling to US addresses will be $2.95. And, going the other direction, shipping is FREE on orders over $70 in the US. The normal $1.95 shipping in the US still applies for orders from $14 to $70.
I also have a number of new Microchip programmers, lab boards, etc, such as ICD-2, PicStart Plus programmers, etc. All brand new in the factory packaging. I'm planning to offer them on eBay, but email if you would like first shot at them.
I will still be "around" to handle any customer service issues that may come up. Who knows... maybe I'll actually have time for an occasional project, instead of just enjoying hearing about yours. :o) I'd like to finally add some projects and info to this website - it won't just disappear after the inventory is gone. Based on the questions I frequently receive, there still seems to be a need for information about using certain devices - including the newer PICs. I've always wanted to add info articles to the website, and now maybe I'll have time to do it.
Thank you very much,Randy Jones, KE7DRRrandy@glitchbuster.comReno/Tahoe, Nevada USA (...At the north end of the Ponderosa, if you've ever seen that burning map at the beginning or end of those old Bonanza westerns. Virginia City, Lake Tahoe, Reno, and Carson City are all just a short "ride" from here.)
PS - IMPORTANT EMAIL NOTE: You may notice that my replies to your email sometimes use odd wording... This is because I'm doing my best to avoid having my email to you "disappear" into spam filters. Things like "free shipping" etc. are very bad, and even short, simple messages discussing details of a transaction have often been relegated to "spam" status. If you don't receive my email please check your spam/junk folder or email me again to let me know that you didn't receive it. I'll then do everything possible to send you a reply that makes it "under the radar.
AC adapter, wall transformer, power pack – they go by many names, but the most popular seems to be "wall wart." Although they are indeed an "unsightly protuberance," they look pretty good to me most of the time…
When I was a high school student building my first ham radio gear, a low voltage DC power supply meant buying a transformer, aluminum box, power cord, terminal strips, hardware, feet, grommets, diodes, and capacitors. Then you drilled, assembled, soldered, and hoped it didn’t start a fire or shock anyone. Buying the whole thing ready to go for a few bucks suddenly doesn’t seem so bad, even if they do tend to clog up a power outlet strip – or look like a wart on your wall...
Most wall warts feed AC power from the wall outlet into a "step-down" transformer, which reduces the voltage to the desired level in its output or "secondary" winding. A few wall warts are much lighter than normal for their size and power rating, and they typically have fancier "switch mode" power supplies like the ones in your PC, TV, or laptop computer. Right now we’ll focus on the far more common warts with a traditional step-down transformer…
There are two major categories: those with AC output, and those with DC output. The warts with AC output don’t have a whole lot more than the transformer inside the plastic "brick." The DC variety has diodes – typically four – to "rectify" the AC to DC, and maybe a capacitor on the output to filter the voltage peaks left over from the AC.
One thing they almost never have is voltage regulation, and that’s very important to understand, since it can create questions and concerns… like: How come I’m reading 20+ volts from my 15 volt wart? Will it damage my xxxx? Is it defective? Actually, it’s perfectly normal. Let’s see why…
Any time we have current flowing through a normal conductor there is a voltage drop. More current, more voltage drop – as stated by Mr. Ohm’s famous law. And the wire used for the windings of your wall wart's transformer is no exception. I have a shiny new "AC adapter" rated at 15 volts DC at 500 mA right here on the bench. What happens when I plug it in to the 120 volt outlet and measure the output? About 20.3 volts, that’s what. So... what’s going on? Did they miss the specified voltage by over 30%? Nope…
This is the "open circuit" voltage – there is no "load" on the wart, so there is no current flowing through the resistance in the transformer’s secondary winding. Thus, no voltage drop.
What happens if we connect a "load" to the wart’s output which requires the rated 500 mA? Now there is a substantial current flowing, and a corresponding voltage drop in the secondary winding. How much drop? Enough to get the voltage down around the wart’s rating – 15 volts in this case. There will be some variation depending on the exact voltage available at your wall outlet, and other factors.
What if the load only "draws" about 100 mA of current? There will be some voltage drop in the transformer, but not as much as when it was supplying 500 mA. So the output voltage will be somewhere between the "open circuit" voltage and the "full load" voltage. The wart I’m using for this example delivers over 18 volts at 100 mA, with 120 volts AC at the wall outlet. What if the wall outlet voltage was lower… like when we have the vacuum cleaner on? Since the wart’s output voltage is not regulated, it will also be lower. Less voltage in, less voltage out.
So, when we select a wall wart for a particular application, several things need to be considered…
Will it be able to maintain the required voltage when delivering the maximum current demanded by the application – even if the wall outlet voltage is a bit low?
Does it have a little "breathing room" – rather than running at its maximum output specification? Since wall warts tend to be kind of chea… er, inexpensive, running them at their maximum rating might not be the best plan.
Is it UL listed, and does the appearance give the impression of quality rather than shoddiness? I’ve seen some pretty crude looking electronic components, and it doesn’t give me that warm and fuzzy feeling of solid reliability. Heck, it’s possible that they may spend a little to make it look nice on the outside and put junk on the inside, but the opposite seems far less likely. A Class 2 rating, which relates to shock hazard, isn’t a bad thing either.
So, let’s say you wanted a wart that would output 100 mA at a minimum of 16 volts DC for a PIC programmer. I wouldn’t select a wart rated at 16 volts DC and 100 mA for two reasons: One, it would be running at its maximum rating and might not be too happy about it. Two, there isn’t much margin for lower than normal wall output voltage (or if the wart doesn’t quite meet specifications).
How about the wart we’ve been using as an example? It can deliver over 18 volts at 100 mA. Is that too much? What if the wall voltage was below normal – perhaps a minor brownout. If the voltage output from this wart is 10% below normal, it still exceeds the required 16 volts. Not too bad! And, at the 100 mA needed by many PIC programmers, for example, we’re only demanding 20% of the wart’s maximum rated current of 500mA. So it’s not working very hard, and should therefore lead a long and happy life.
Next time we’ll explore a related topic – selecting and using those wonderful 3-pin voltage regulator ICs to convert unregulated wall wart output to the voltage our project requires…
When I was a high school student building my first ham radio gear, a low voltage DC power supply meant buying a transformer, aluminum box, power cord, terminal strips, hardware, feet, grommets, diodes, and capacitors. Then you drilled, assembled, soldered, and hoped it didn’t start a fire or shock anyone. Buying the whole thing ready to go for a few bucks suddenly doesn’t seem so bad, even if they do tend to clog up a power outlet strip – or look like a wart on your wall...
Most wall warts feed AC power from the wall outlet into a "step-down" transformer, which reduces the voltage to the desired level in its output or "secondary" winding. A few wall warts are much lighter than normal for their size and power rating, and they typically have fancier "switch mode" power supplies like the ones in your PC, TV, or laptop computer. Right now we’ll focus on the far more common warts with a traditional step-down transformer…
There are two major categories: those with AC output, and those with DC output. The warts with AC output don’t have a whole lot more than the transformer inside the plastic "brick." The DC variety has diodes – typically four – to "rectify" the AC to DC, and maybe a capacitor on the output to filter the voltage peaks left over from the AC.
One thing they almost never have is voltage regulation, and that’s very important to understand, since it can create questions and concerns… like: How come I’m reading 20+ volts from my 15 volt wart? Will it damage my xxxx? Is it defective? Actually, it’s perfectly normal. Let’s see why…
Any time we have current flowing through a normal conductor there is a voltage drop. More current, more voltage drop – as stated by Mr. Ohm’s famous law. And the wire used for the windings of your wall wart's transformer is no exception. I have a shiny new "AC adapter" rated at 15 volts DC at 500 mA right here on the bench. What happens when I plug it in to the 120 volt outlet and measure the output? About 20.3 volts, that’s what. So... what’s going on? Did they miss the specified voltage by over 30%? Nope…
This is the "open circuit" voltage – there is no "load" on the wart, so there is no current flowing through the resistance in the transformer’s secondary winding. Thus, no voltage drop.
What happens if we connect a "load" to the wart’s output which requires the rated 500 mA? Now there is a substantial current flowing, and a corresponding voltage drop in the secondary winding. How much drop? Enough to get the voltage down around the wart’s rating – 15 volts in this case. There will be some variation depending on the exact voltage available at your wall outlet, and other factors.
What if the load only "draws" about 100 mA of current? There will be some voltage drop in the transformer, but not as much as when it was supplying 500 mA. So the output voltage will be somewhere between the "open circuit" voltage and the "full load" voltage. The wart I’m using for this example delivers over 18 volts at 100 mA, with 120 volts AC at the wall outlet. What if the wall outlet voltage was lower… like when we have the vacuum cleaner on? Since the wart’s output voltage is not regulated, it will also be lower. Less voltage in, less voltage out.
So, when we select a wall wart for a particular application, several things need to be considered…
Will it be able to maintain the required voltage when delivering the maximum current demanded by the application – even if the wall outlet voltage is a bit low?
Does it have a little "breathing room" – rather than running at its maximum output specification? Since wall warts tend to be kind of chea… er, inexpensive, running them at their maximum rating might not be the best plan.
Is it UL listed, and does the appearance give the impression of quality rather than shoddiness? I’ve seen some pretty crude looking electronic components, and it doesn’t give me that warm and fuzzy feeling of solid reliability. Heck, it’s possible that they may spend a little to make it look nice on the outside and put junk on the inside, but the opposite seems far less likely. A Class 2 rating, which relates to shock hazard, isn’t a bad thing either.
So, let’s say you wanted a wart that would output 100 mA at a minimum of 16 volts DC for a PIC programmer. I wouldn’t select a wart rated at 16 volts DC and 100 mA for two reasons: One, it would be running at its maximum rating and might not be too happy about it. Two, there isn’t much margin for lower than normal wall output voltage (or if the wart doesn’t quite meet specifications).
How about the wart we’ve been using as an example? It can deliver over 18 volts at 100 mA. Is that too much? What if the wall voltage was below normal – perhaps a minor brownout. If the voltage output from this wart is 10% below normal, it still exceeds the required 16 volts. Not too bad! And, at the 100 mA needed by many PIC programmers, for example, we’re only demanding 20% of the wart’s maximum rated current of 500mA. So it’s not working very hard, and should therefore lead a long and happy life.
Next time we’ll explore a related topic – selecting and using those wonderful 3-pin voltage regulator ICs to convert unregulated wall wart output to the voltage our project requires…