tag:blogger.com,1999:blog-6615160292280278140.post2380597615863576738..comments2024-03-28T08:07:01.529-04:00Comments on Hands On - Make: Electronics: AC Adapter CheckJames Floyd Kelly (Jim)http://www.blogger.com/profile/13876934942928389738noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-6615160292280278140.post-54239248705651485002010-06-07T00:42:54.421-04:002010-06-07T00:42:54.421-04:00Does anyone know where I can get a similar adapter...Does anyone know where I can get a similar adapter from another shop? I'm from Canada but a number of the sites that sell components also ship here i.e. mouser, allelectronics, 123active, etc.Unknownhttps://www.blogger.com/profile/12688393041185049598noreply@blogger.comtag:blogger.com,1999:blog-6615160292280278140.post-26947010359474772702010-03-04T21:24:25.083-05:002010-03-04T21:24:25.083-05:00BTW, the part number for the AC adapter is incorre...BTW, the part number for the AC adapter is incorrect. I found it at radioshack.com as Model: 273-316<br /><br />Keep up the good work!gabepetehttps://www.blogger.com/profile/10479101974178464002noreply@blogger.comtag:blogger.com,1999:blog-6615160292280278140.post-1556765146669538392010-01-23T11:24:17.096-05:002010-01-23T11:24:17.096-05:00One of the most frustrating puzzles I had early on...One of the most frustrating puzzles I had early on was the same you mention here with the rails of your board not going the full length of the board. For the longest time I couldn't figure it out. It still gets me occasionally. <br /><br />I've found a lot of the components that I use have tolerances in their voltage requirements. For instance, an LED strip I'm working with allows for up to 12.5v, even though it states that it runs on 12v.Aaronhttps://www.blogger.com/profile/03821060961655934831noreply@blogger.comtag:blogger.com,1999:blog-6615160292280278140.post-29116093725273217842010-01-19T21:59:09.580-05:002010-01-19T21:59:09.580-05:00"Wall wart" power adapters are cheap and..."Wall wart" power adapters are cheap and nasty things. As noted, their output voltage will decrease if you load them. I used them in my book because for my experiments, they are good enough. When you get to chips, though, you will find that I quickly introduce a voltage regulator, since there is no way a Shack adapter will give you 5.0 volts precisely. And I use the obligatory capacitors to suppress the ripple that you get from AC adapters.Charles Platthttps://www.blogger.com/profile/00968751199924367578noreply@blogger.comtag:blogger.com,1999:blog-6615160292280278140.post-82061581819404064062010-01-16T03:17:42.908-05:002010-01-16T03:17:42.908-05:00Brian: That is because you need to have a load on ...Brian: That is because you need to have a load on the power supply in order to see the real voltage. A load meaning something actually using power from the supply such as an array of LEDs or even the relay switch pulling the contacts to a closed state.<br /><br />Also a good reason why to have a power regulator between electronics and the supply to prevent such a high voltage in the beginning before the loud pulls it down.Nathan M.https://www.blogger.com/profile/16595108335094595631noreply@blogger.comtag:blogger.com,1999:blog-6615160292280278140.post-18072999903018457672010-01-15T20:25:53.492-05:002010-01-15T20:25:53.492-05:00My adapter (stolen from a dead cordless phone) is ...My adapter (stolen from a dead cordless phone) is labeled 9V, 300mA, but the meter reads around 16 volts!<br /><br />I put at 2.2K resistor across it, and that dropped it down, but only by about half a volt.Unknownhttps://www.blogger.com/profile/03534660003397028937noreply@blogger.comtag:blogger.com,1999:blog-6615160292280278140.post-80318872212405047682010-01-15T20:03:53.068-05:002010-01-15T20:03:53.068-05:00I assume that you did the Voltage test open circui...I assume that you did the Voltage test open circuit. If you put a resistor across the outputs the Voltage will go down. This will also happen if you do it with a battery. The adapter will probably put out the rated Voltage when the current maximum in the manual is reached.<br /><br />You have discovered that real DC supplies are more complicated than the simple theory in beginning texts. Usually a better DC supply model is introduced at the end of the DC theory semester, at least were I went to school.<br /><br />You are on track. It would not do any harm to verify the Voltage source with a meter when you take reading for your calculations.pbenhttps://www.blogger.com/profile/05685131193395252858noreply@blogger.com