RE: MD: External MD Power Supply for 722
Larry Sherry wrote: I'm not sure if you are stating that the external power adapter that comes with the Sharps have special circuitry in them. But as far as I can tell they are cheap bricks made in China. Not necessarily. My European MD-MS200 came with a very nice, small, light, regulated power supply. The label says it can take anything from 110 to 240 V. Still no 'special circuitry', but obviously it is different from the one you recieved. BTW, the one that came with my more current European MD-S321 is limited to 220-240 V. old Sharp 200 (btw, this unit is in my humble opinion one of the best portable recorders ever made-it may not have all of the bells and whistles of the newer units but it is a well made, trouble free unit with excellent sound reproduction. Yes, I think so, too. And although it is huge compared to current recorders, only the latest models can beat its battery life, epecially with its 6 AA external battery pack. Bye Martin - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
--- Mike Burger [EMAIL PROTECTED] wrote: My understanding is that the 5 volt requirement is for the charging circuit. I would think that by applying a lower voltage source, the charging circuit just wouldn't engage... Thats what I thought, but I can charge mine off the same 4.5VDC supply. I did manage to destroy one adaptor during my testing phase, but that was because it couldn't supply the necessary current, so it fried itself. Any adaptor with a current output in excess of 600mA should work fine, whether it is at 4.5V or 5V. Ian = "First, there were some amoebas. Deviant amoebas adapted better to the environment, thus becoming monkeys. Then came Total Quality Management." -- Scott Adams http://www.btinternet.com/~ighorsey __ Do You Yahoo!? Kick off your party with Yahoo! Invites. http://invites.yahoo.com/ - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
I think you will find that a true, regulated 4.5v will not charge the battery. A 5.0 regulated supply will... Maybe some 4.5v supplies are actually closer to 5v? GB - Original Message - Thats what I thought, but I can charge mine off the same 4.5VDC supply. I did manage to destroy one adaptor during my testing phase, but that was because it couldn't supply the necessary current, so it fried itself. Any adaptor with a current output in excess of 600mA should work fine, whether it is at 4.5V or 5V. Ian - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
Since I asked this question about the Radio Shack "Portable CD Player Power Pack" (23-505) rechargeable lead battery, I have gone ahead and used it with the 722. The unit functions quite well except that the "battery charging" indicator never goes out. So it would seem that the internal battery is not being charged, at least not effectively. So, does that mean that it is possibly being discharged while the external battery (3 - 4.5 nominal voltage) is attached? How does the Sharp prioritize battery drain anyway? If, for example, I have the Sharp battery pack installed and a freshly charged internal battery, which is the primary current supplier to the unit? Thanks for all the info thus far. Jim Lee Graham Baker wrote: I think you will find that a true, regulated 4.5v will not charge the battery. A 5.0 regulated supply will... Maybe some 4.5v supplies are actually closer to 5v? GB - Original Message - Thats what I thought, but I can charge mine off the same 4.5VDC supply. I did manage to destroy one adaptor during my testing phase, but that was because it couldn't supply the necessary current, so it fried itself. Any adaptor with a current output in excess of 600mA should work fine, whether it is at 4.5V or 5V. Ian - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED] -- == James S. Lee| Net: [EMAIL PROTECTED] Communication Studies, CB# 6235 | Phn: 919-962-4963 University of North Carolina - CH | Fax: 919-962-3305 Chapel Hill, NC 27599-6235 | Web: www.unc.edu/~jimlee/ == - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
- Original Message - From: James S. Lee [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, 4 August 2000 11:16 Subject: Re: MD: External MD Power Supply for 722 Since I asked this question about the Radio Shack "Portable CD Player Power Pack" (23-505) rechargeable lead battery, I have gone ahead and used it with the 722. The unit functions quite well except that the "battery charging" indicator never goes out. So it would seem that the internal battery is not being charged, at least not effectively. So, does that mean that it is possibly being discharged while the external battery (3 - 4.5 nominal voltage) is attached? No I don't think so. The connection between the external batteries and the internal one would at least have a diode in between to stop inter-action and I suspect it would be far more complex than that, using the voltage regulator chip to switch between battery supplies. The Sharp 701/702 voltage regulator chip is quite smart - it recognises different voltages from different sources (incl car jack) and controls it accordingly. I had the same problem with a RS 4.5v power pack - it would drive the player but not charge the battery. In the end I built a 5v regulated supply, using an ic and capacitor and fed this with 7.5v from the RS power pack. The 5v is rock solid and charges the battery perfectly. I have a circuit somewhere if you are interested, thanks to another (can't remember who) MD-L contributor. How does the Sharp prioritize battery drain anyway? If, for example, I have the Sharp battery pack installed and a freshly charged internal battery, which is the primary current supplier to the unit? If you have a charged internal cell and the external battery pack fitted the (701) recorder uses the internal supply first and then changes to the external supply, without stopping record or playback. GB - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
My own personal 701 experience... The original internal battery recently began to fail. However I had 12x 4V lithium cells laying around doing nothing (from an old laptop battery where the circuitry died not the batteries) Now the internal battery is 3.6V where as these were 4V... Hmm, voltage a bit off, but I decided to give it a try. I made up a "Dummy" battery where the terminals lead off to the outside. Only mod I had to make was to the battery cover to enable the wire to get out. I hooked up the battery... and no smoke (boy was I relieved!) Power on and everything works OK! After a quick test I made the connection semi permanent and left it playing. 10 Hours later its still going and on the last battery bar. Interestings thing to note - With the fully charged Lithium connected it thought it was connected to the power adapter! When the Lithium was then recharged by the MD it was charged back up to the Preset point suitable for the 3.6V original. After that (not REALLY fully charged Lithium) I've been getting about 6-8 hours playtime. At some point I'll make up a charger to FULLY charge the lithium and then run from that. -- James Budworth [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED] ICQ# Tsuki_yomi - 684547 The Complete Clow http://www.techserv.curtin.edu.au/tsuki_yomi/clow/clow.htm The Ranmascan Project (Australian Mirror) http://www.techserv.curtin.edu.au/ranmascan/ - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
I'm not sure if you are stating that the external power adapter that comes with the Sharps have special circuitry in them. But as far as I can tell they are cheap bricks made in China. I think that it has more to do with the voltage then the power supply. I have had a constant on going argument with the owner of the now defunct MiniDisc Now. He once sent me what he claimed was a "universal" adapter. It is a cheap piece of crap from some off shore country. It had a tiny selector on it that stated 100v/220/. I tried to explain to him that this adapter was no better in the US then the original adapter that comes with the Japanese domestic units. He gave me some bullsh!t about having tested it. It was just that. I have never owned a Sharp 702 or later Sharp model. But I do have a Denon 70P which is a Sharp 200 clone. If you try to use the adapter supplied with the unit where I live the unit will not work. You get the word "power" on the LCD. Plugging a 100 volt adapter into an outlet that can vary from 110 to 120 volts (I think that the national average is about 117), is going to supply more voltage then the unit can handle. Perhaps on the newer units the circuitry is more forgiving. But not on the old Sharp 200 (btw, this unit is in my humble opinion one of the best portable recorders ever made-it may not have all of the bells and whistles of the newer units but it is a well made, trouble free unit with excellent sound reproduction.-Althought it comes with a a simple remote, I bought an LCD remote for it. It's not back lit, but looks like it is of much better quality then the current remotes. It is actually made of METAL. Not painted to try and present a poor imitation of metal, like my Aiwa F70). Larry Graham Baker wrote: - Original Message - From: James S. Lee [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, 4 August 2000 11:16 Subject: Re: MD: External MD Power Supply for 722 Since I asked this question about the Radio Shack "Portable CD Player Power Pack" (23-505) rechargeable lead battery, I have gone ahead and used it with the 722. The unit functions quite well except that the "battery charging" indicator never goes out. So it would seem that the internal battery is not being charged, at least not effectively. So, does that mean that it is possibly being discharged while the external battery (3 - 4.5 nominal voltage) is attached? No I don't think so. The connection between the external batteries and the internal one would at least have a diode in between to stop inter-action and I suspect it would be far more complex than that, using the voltage regulator chip to switch between battery supplies. The Sharp 701/702 voltage regulator chip is quite smart - it recognises different voltages from different sources (incl car jack) and controls it accordingly. I had the same problem with a RS 4.5v power pack - it would drive the player but not charge the battery. In the end I built a 5v regulated supply, using an ic and capacitor and fed this with 7.5v from the RS power pack. The 5v is rock solid and charges the battery perfectly. I have a circuit somewhere if you are interested, thanks to another (can't remember who) MD-L contributor. How does the Sharp prioritize battery drain anyway? If, for example, I have the Sharp battery pack installed and a freshly charged internal battery, which is the primary current supplier to the unit? If you have a charged internal cell and the external battery pack fitted the (701) recorder uses the internal supply first and then changes to the external supply, without stopping record or playback. GB - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED] - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
Providing the power pack can supply the current, then it should power the 722 just fine. I power my 702 off a Sony 4.5VDC mains adaptor and I have never had any problems with it. Ian = "First, there were some amoebas. Deviant amoebas adapted better to the environment, thus becoming monkeys. Then came Total Quality Management." -- Scott Adams http://www.btinternet.com/~ighorsey __ Do You Yahoo!? Kick off your party with Yahoo! Invites. http://invites.yahoo.com/ - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
My understanding is that the 5 volt requirement is for the charging circuit. I would think that by applying a lower voltage source, the charging circuit just wouldn't engage... On Wed, 2 Aug 2000, James S. Lee wrote: I use a Radio Shack "Portable CD Player Power Pack" (23-505) to power my Sony PCM-M1 DAT recorder. The unit is essentially a CD-sized rechargeable lead acid battery. I get hours of hum-free operation from each charge. It's great. Now I am wondering if this device will work just as well with my Sharp 722 MD recorder. The battery has a nominal 3 - 4.5 volt output, below the specified 5 volts called for by the 722. Any thoughts? Would the relatively low voltage of the battery do any damage by undercharging the Sharp battery? Any danger at all? - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
RE: MD: External MD Power Supply for 722
Only thing is though, it won't charge any rechargeable batteries because of the 0.5V discrepancy. Adios, LarZ --- TAMA - The Strongest Name in Drums --- -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Ian Horsey Sent: Thursday, 3 August 2000 12:03 To: [EMAIL PROTECTED] Subject:Re: MD: External MD Power Supply for 722 Providing the power pack can supply the current, then it should power the 722 just fine. I power my 702 off a Sony 4.5VDC mains adaptor and I have never had any problems with it. Ian = "First, there were some amoebas. Deviant amoebas adapted better to the environment, thus becoming monkeys. Then came Total Quality Management." -- Scott Adams http://www.btinternet.com/~ighorsey __ Do You Yahoo!? Kick off your party with Yahoo! Invites. http://invites.yahoo.com/ - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED] - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
* Ian Horsey [EMAIL PROTECTED] on Wed, 02 Aug 2000 | Providing the power pack can supply the current, then it should power | the 722 just fine. I power my 702 off a Sony 4.5VDC mains adaptor | and I have never had any problems with it. The 702 and 722 have nearly identical power requirements. -- Rat [EMAIL PROTECTED]\ Do not use Happy Fun Ball on concrete. Minion of Nathan - Nathan says Hi! \ PGP Key: at a key server near you! \ - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
As does the MT15. On Wed, 2 Aug 2000, Stainless Steel Rat wrote: * Ian Horsey [EMAIL PROTECTED] on Wed, 02 Aug 2000 | Providing the power pack can supply the current, then it should power | the 722 just fine. I power my 702 off a Sony 4.5VDC mains adaptor | and I have never had any problems with it. The 702 and 722 have nearly identical power requirements. - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
You could get one of the computer cards that you can set to output any voltage you want. They are only $10 or $20 US, depending one the model, when I bought one in Germany a few months ago. Of course youwould have toi carry your computer around. Stainless Steel Rat wrote: * Ian Horsey [EMAIL PROTECTED] on Wed, 02 Aug 2000 | Providing the power pack can supply the current, then it should power | the 722 just fine. I power my 702 off a Sony 4.5VDC mains adaptor | and I have never had any problems with it. The 702 and 722 have nearly identical power requirements. -- Rat [EMAIL PROTECTED]\ Do not use Happy Fun Ball on concrete. Minion of Nathan - Nathan says Hi! \ PGP Key: at a key server near you! \ - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED] -- Jim Coon Not just another pretty mandolin picker. mailto:[EMAIL PROTECTED] If Gibson made cars, would they sound so sweet? My first web page http://www.tir.com/~liteways - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
Re: MD: External MD Power Supply for 722
You could get one of the computer cards that you can set to output any voltage you want. They are only $10 or $20 US, depending one the model, when I bought one in Germany a few months ago. Of course youwould have toi carry your computer around. Good practical advice there Jim, actually it may be easier to carry around your full size MD and Amp seperates plus speakers. H... Yours in jest, PrinceGaz. - To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
