开云体育

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of prea
Sent: 23 January 2021 11:54
To: [email protected]
Subject: Re: [YamahaQY70AndQY100] QY100 display light

Hi Kaltar, that's as usual a great contribution... I particularly like the measurements you made on the (to me useless) TO HOST connectors...
actually, next month when the new frontlight will came, I thin I will consider that... normally, when I need the LDC light I'm not using MIDI and I have hte QY disconnected from everything (but the powe supply, perhaps).

Re: gooseneck lamp, this make me thing to those PS/2 to USB mouse adapters of good old times, I should have some lurking in a drawer at the office, and if all holds from a purely mechanical standpoint, shouldn't be a difficult job, there should also be room for the resistors...

Will give a try, maybe next week I'll go scavenging in the office, in these lockdown times (I'm in Lombardy, Italy, and it's almost a year
now) moving can be problematic, even if my office is 10 mins on foot form home...

stay safe everybody

On 20/01/21 18:48, kaltar wrote:

Prea,

When I took my QY100 out of it's box for the first time after being
there for decades, I realized the lighting problem too. That's why we
briefly talked about it in the QY700 forum.
I went out and took notes on all current available in the QY ports,
and ended up with a non invasive method of a light for a QY70 and QY100:

1) In the "to host" port, between pins 4 (GND) and 8 (RxD+) you get
3.61V and 107.3mA, that's 383 mW!
That is enough power to light 20 conventional LEDs!

2) Have you seen a USB gooseneck lamp? well, we can built one but
instead of USB, an 8 pin mini din.
The 8 pin mini din jack is $1 USD or less. The mini din jack has
enough strength to hold a gooseneck lamp.

3) Many USB lamps can be canibalized to remove the lamp and neck section.

4) USB lamps are set for 5V 500mA, but depending on the USB lamp we
could see internal resistors for that voltage in the lamp section.
We could fit/change the lamp casing board with a 3 Ohms 50mW
resistor, and that would be enough to support up to 20 parallel LEDs
in the lamp
(assuming they are standard). Or if they are not standard, built a
little circuit tablet with the LEDs and the resistor.

What do you think?