So i was connecting my portable cassette players through AC power. They - philips aq6401 & grundig bb36 - have a 3dc volt socket. My unic rv-52 has a 4.5dc volt socket. I powered them up through a 1000mA rotary switch adapter by goobay. All three devices are working fine. But i was wondering: can my laptop power up my portable cassette player too through a usb to DC adaper cable?
Hi .. the usb connection is always at 5 volts you will have to reduce it a bit to go from 5 to 3 volts .... a laptop generally manages to power the keys usb that consume a few mA I don't know if it can keep a walkman
A standard USB connection is rated for 500mA so a Walkman should be no problem at all. I would hope that any cable had some kind of regulator to step it down to the voltage e.g 3V that the Walkman needs. Sticking 5V into equipment designed for 3V wouldn't be a good idea. 5V would be OK for equipment designed for 6V. Four NiMH batteries only give you 4.8V/
Lets say i buy a universal charger usb to DC cable. And i plug the usb into a usb step down converter Will that be the solution?
That is an interesting device that should be good for the 3V Walkman. Just make sure you doñt accidentally select one of the higher voltages. Another downside is that I notice that the output is screw terminals rather than something you could plug one of the leads you show into. The Device doesn't do 4.5V but 5V directly would probably be O.K. for that. Can you solder ? A simple 5V to 3V regulator circuit using something like an LM317 would require about five components. Alternatively you could buy one ready made https://www.ebay.co.uk/itm/LM317-DC...339022?hash=item3da979d54e:g:VVwAAOSwH1RfO1S8 That is a bargain. Fourty years ago the DVM module would have cost as much as something like a Sony WM22.
as Longman says in 5 minutes you can do this ... if you can solder .... and the cost is much lower than other solutions ... the diodes put in series make the voltage drop by about 0.6 volts for one ... 3 in series should suffice. Alternatively you can use a regulator like this in the shape of a transistor that is already set at 3.3 volts at the output https://www.ebay.it/itm/LOW-DROPOUT...croelectronics&_trksid=p2047675.c100010.m2109
You are right, I forgot this "little" yet important detail. It's all about pug & play, since I can not solder. It's funny, so incredible much products on Emazonexpress but no plug & play usb dc step down switch adaptor
Well screw terminals don't need a soldering iron. However, I would recommend getting a test meter to check polarity etc. It could be useful for all sorts of things like checking batteries and headphones. A £5 one e.g https://www.ebay.co.uk/itm/Mini-Poc...894318?hash=item1cf0f862ae:g:dhoAAOSwXu1fOkxV is adequate for a beginner. A couple of years ago I wired a complete telephone system using a £5 analogue meter as it was all I had available at my Mum's house.
I had to read this sentence twice "screw" has different meanings . The thing is that such a step down adapter had to have a female usb-terminal "out", so usb 5v from laptop to usb 3v / 4.5v (or just fixed 3v) as a selling product so i can plug in a usb to dc cable to the step-down adapter. Some reading on the internet states that such a product does not exist, nor wil be brought on the market. Thanks for the suggestion for the volt-meter!
USB is all defined in a standard which has only been around since 1996, and which will probably be completely superceded by USB-C in a decade or two. I can understand why a manufacturer wouldn't want to put a USB socket on something that wasn't even attemping to meet the standards. Screw terminals have been around since before anyone had ever thought of electronics, are more versatile, and will probably still be around in another hundred years (if civilisation is).
