With 240V mains and no load the mains Tx is saturating with , not too
intrusive laminations buzz, with a current draw of .34 amps , normal? Tx
seems adequate size for this combo
In for "stuck" tuner display. One LED solder bridge from manufacture, cannot
ever have displayed, must have eventually draggged down 74HCT595 and now all
LED are on for flat/sharp section, other section , main scale note DISPLAY ,
and its 595 working .

just about to order some ( minimum order constraints) 74HCT595 and I noticed
it is actually 74AHCT595 perhaps I will try a repinned 74HC4094 that I have
laying around

N_Cook wrote:

just about to order some ( minimum order constraints) 74HCT595 and I noticed
it is actually 74AHCT595 perhaps I will try a repinned 74HC4094 that I have
laying around

How is the 74HCT595 used? We used them as parallel output latches
and cascaded them for more outputs. That will be a lot of work to avoid
a 40 cent part. The stobe polarity is inverted, and the timing is
different. Look at the datasheets.

http://www.nxp.com/documents/data_sheet/74HC_HCT595.pdf

http://www.nxp.com/documents/data_sh...HC_HCT4094.pdf


--
You can't have a sense of humor, if you have no sense.

Michael A. Terrell wrote in message
m...

N_Cook wrote:

just about to order some ( minimum order constraints) 74HCT595 and I
noticed
it is actually 74AHCT595 perhaps I will try a repinned 74HC4094 that I
have
laying around

How is the 74HCT595 used? We used them as parallel output latches
and cascaded them for more outputs. That will be a lot of work to avoid
a 40 cent part. The stobe polarity is inverted, and the timing is
different. Look at the datasheets.

http://www.nxp.com/documents/data_sheet/74HC_HCT595.pdf

http://www.nxp.com/documents/data_sh...HC_HCT4094.pdf


--
You can't have a sense of humor, if you have no sense.


I'm more concerned about the 1/3 amp of current of saturation , checked with
the secondaries disconnected. Such equipment would have been condemned where
I used to work, but I assume anything goes these days, made for UK with 230V
on the rating plate. Does this sort of thing come into CE compliance?
backhanders from the utility companies to increase consumption ?

I confirmed the SD-IN is valid , lashing up a 4015 and will probably get
some HCT595 as there seems just one seriously over-priced supplier in the uk
of AHCT595. Probably Fender having a job lot of the HCT rather than some
on-the-edge of envelope AHCT spec requirement for this use. But as a
backstop I now know the central in-tune LED only is an option with a 4015,
without the flat and sharp direction LEDs. The main scale note LEDs are
driven from another 595

worked with a 74HC595 replacement for the 74AHCT595