PSR Tutorial Forum

PSR Keyboards (11 Boards) => PSR-E Series => Topic started by: ACSACS on November 24, 2021, 03:46:37 PM

Title: Batteries and PSU together PSR E363?
Post by: ACSACS on November 24, 2021, 03:46:37 PM
If I have batteries installed and I also plug in the PSU, which will the keyboard draw power from?

Thanks
Title: Re: Batteries and PSU together PSR E363?
Post by: SeaGtGruff on November 24, 2021, 07:41:08 PM
I don't think that's recommended. If you're going to plug the keyboard into a power socket using the power adapter, you should first remove any batteries from the battery compartment.
Title: Re: Batteries and PSU together PSR E363?
Post by: johan on November 24, 2021, 09:12:38 PM
The batteries are disconnected automatically when you connect the power adapter.
Title: Re: Batteries and PSU together PSR E363?
Post by: overover on November 25, 2021, 12:36:10 AM
If I have batteries installed and I also plug in the PSU, which will the keyboard draw power from?

Thanks

Hi ACSACS,

johan is correct: When connecting the DC plug of the AC adapter to the DC IN jack of the PSR-E363, the minus pole of the batteries is automatically disconnected from the device by an internal switching contact of the DC IN jack, and power will be automatically drawn from the AC adapter only.

Note: When the batteries run out, or if the instrument is not to be used for a long time, remove the batteries from the instrument to prevent damage from possible battery leakage.

In connection with batteries, please also pay attention to the instructions in the E363 Owner's Manual, pages 12/13. If required, you can download the manual here:
>>> https://uk.yamaha.com/files/download/other_assets/7/890277/psre363_en_om_b0.pdf


By the way, depending on the battery type to be used (rechargeable or not), you may need to change the battery type setting on this instrument (via Function number 046).


Best regards,
Chris
Title: Re: Batteries and PSU together PSR E363?
Post by: MikeS on November 25, 2021, 02:19:02 AM
I have an E443 and the circuit diagram shows the power pack only removing a short circuit around two diodes in series with the with the -ve battery rail. See attached. With the power pack installed the E443 only draws power from the power pack because the diodes have -9V or -7.2V at the battery end and -12V from the plug pack which turns the diodes off. For the diodes to be on the voltage at the battery end has to be higher -ve voltage than the voltage from the plug pack.

If there is a mains power fail while playing, the diodes will turn on and supply power from the battery, however the voltage drop across the two diodes means you are effectively running on 1 less battery so run time is reduced. On mains fail unplug the power pack from the keyboard if you want maximum run time from the batteries.

I do not  have an E363 service manual, but I suspect it will be the same.

Title: Re: Batteries and PSU together PSR E363?
Post by: overover on November 25, 2021, 05:00:46 AM
I have an E443 and the circuit diagram shows the power pack only removing a short circuit around two diodes in series with the with the -ve battery rail. See attached. With the power pack installed the E443 only draws power from the power pack because the diodes have -9V or -7.2V at the battery end and -12V from the plug pack which turns the diodes off. For the diodes to be on the voltage at the battery end has to be higher -ve voltage than the voltage from the plug pack.

If there is a mains power fail while playing, the diodes will turn on and supply power from the battery, however the voltage drop across the two diodes means you are effectively running on 1 less battery so run time is reduced. On mains fail unplug the power pack from the keyboard if you want maximum run time from the batteries.

I do not  have an E363 service manual, but I suspect it will be the same.

Hi MikeS,

Yes, the circuit near the DC IN jack on PSR-E models, which can also be operated with batteries, will be almost identical. I don't have the E363 Service Manual either at the moment. But I looked in the Service Manuals of several similar models, including the one from the E353:

The diodes D506 and D507 (type 10EDA40-TA1B2) you mentioned are obviously NOT INSTALLED, because they are surrounded in the circuit diagram with a dotted line, which means "The parts which are surrounded by dotted line are No mount." Neither could I find these two diodes in the "Electrical Parts list" of the Service Manual.

So it is very likely with the E363, as I described above, that when connecting the DC plug, the negative pole of the battery pack is completely disconnected from the internal circuit. See also the attached picture.


Best regards,
Chris
Title: Re: Batteries and PSU together PSR E363?
Post by: MikeS on November 25, 2021, 05:38:32 AM
Looks like Yamaha has saved themselves a few cents per keyboard by removing the diodes. They are present in the E443 as the keyboard will operated from battery with the plug inserted but no mains power applied. Useful UPS function but battery life is very poor with plug inserted, about 3 hours vs 10 hours with plug out using rechargeable batteries.

Title: Re: Batteries and PSU together PSR E363?
Post by: overover on November 25, 2021, 08:50:43 AM
Looks like Yamaha has saved themselves a few cents per keyboard by removing the diodes. They are present in the E443 as the keyboard will operated from battery with the plug inserted but no mains power applied. Useful UPS function but battery life is very poor with plug inserted, about 3 hours vs 10 hours with plug out using rechargeable batteries.

Thanks for your quick response, MikeS!

Originally I only looked in the Service Manuals of PSR-E3xx models. I have just looked again in various PSR-E Service Manuals: Obviously these two diodes are PRESENT in all PSR-E4xx models, but MISSING in all PSR-E3xx models. ;)


Best regards,
Chris
Title: Re: Batteries and PSU together PSR E363?
Post by: SeaGtGruff on November 26, 2021, 08:48:06 PM
The possibility of using the batteries as a sort of backup in case of power loss is interesting, but I think the main reason Yamaha recommends removing the batteries when using a power adapter is so you don't forget about them and leave them in for so long that they cause damage from corrosion or leakage.
Title: Re: Batteries and PSU together PSR E363?
Post by: pjd on November 27, 2021, 05:26:37 PM
Hi --

If you can possibly endure the tedium, clues are sprinkled throughout the cautionary statements.  :D

The statements mention that a minimal amount of electricity flows from the adapter (and batteries!) when the device is "off." I put "off" in quotes because the power switch is not ON/OFF -- it's ON/Standby. Yes, the standby state will eventually drain the batteries and perhaps hasten leakage.

I didn't understand why my Sonogenic and PSS-A50 drained even when "off." Looked at the schematics and, as usual, wrote a blog entry:  ;D

http://sandsoftwaresound.net/pss-a50-power-to-the-people/

This Panasonic note about battery leakage may be helpful, too:

https://www.panasonic-batteries.com/en/news/battery-leakage-causes-and-prevention

Who knew this could get so complicated?  :)

All the best -- pj
Title: Re: Batteries and PSU together PSR E363?
Post by: ACSACS on December 03, 2021, 07:06:21 PM
Very good to know thankyou