7 Apr
2016
7 Apr
'16
4:41 p.m.
Does this warning assume that there is something on Vin, and not open?
With a quick look at the internal schematic of an old-school 7805, it
seems like what Bill suggests (leaving Vin open) will not actually do
much.
--
Will
On Thu, Apr 7, 2016 at 7:23 PM, John Robertson <jrr at flippers.com> wrote:
On 04/07/2016 2:18 PM, Bill Sudbrink wrote:
drlegendre wrote:
Yes, you can damage the 7805 - READ the data sheets...
Raising the Output Voltage above the Input Voltage:
Since the output of the device does not sink current, forcing
LM340/LM78MXX Series 3-Terminal Positive Regulators LM340/LM78MXX Series
3-Terminal Positive Regulators
the output high can cause damage to internal low current paths in a manner
similar to that just described in the ?Short- ing the Regulator Input?
section.
LM340/LM78MXX Series 3-Terminal Positive Regulato John :-#(#
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
www.flippers.com
"Old pinballers never die, they just flip out"
Not saying it's going to smoke-out, but it does
seem like a wonky thing to do.
I disagree about "wonky" let me try with more
diagram and less English:
(+8)
|
VIN| ceramic cap
|-----][-----
___|____ |
| 7805 |----------GROUND
-------- |
| |
VOUT|(+5) |
| |
___|____ |
| LOAD |-------|
--------
+8 is not currently available (no pun intended).
I would like to test LOAD without removing 7805
as it is soldered in place. Is damage to 7805
likely if alternative regulated current is applied
at (+5) and (+8) is left open?
Bill S.