Today's Message Index:
----------------------
1. 06:24 AM - Re: Re: Power Duece Schottky diodes (Charlie England)
2. 03:50 PM - Re: mystery relay (user9253)
3. 04:09 PM - Re: New role for the E-Bus? (user9253)
4. 07:26 PM - Re: mystery relay (johnbright)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Power Duece Schottky diodes |
On Sat, Feb 22, 2020 at 11:24 PM Randy C-GRPY <rpulis@shaw.ca> wrote:
>
>
> user9253 wrote:
> > Most of the diodes discussed above will drop about 0.5 volts at 10 amps
.
> > The power loss will be 0.5 x 10 = 5 watts. That will produce lots of
> heat.
> > Have you ever touched a 3 watt incandescent night light?
> > So yes, use a heat sink with heat conductive paste.
> > The aircraft structure can serve as a heat sink if it is aluminum.
> > If the diode mounting surface is not electrically insulated from the
> diode terminals, then some
> > type of dielectric heat conductive film must be used between the diode
> and mounting surface.
> > If a TO=88=92220 diode is used, solder wires to the 3 terminals.
> > A coating of E6000 will insulate and protect the terminals from
> vibration.
>
>
> Thank you Joe. I'm going to be mounting the diodes on the subpanel which
> is aluminium and most of the components will be less than 5 amps. Based
on
> what you just said, I think that a heat sink likely isn't necessary other
> than using the panel.
>
> Randy
>
There are some decent articles by Jim Weir in Kitplanes on how to calculate
heat sink size needed. (Unfortunately, the search feature in Kitplanes' web
archive is virtually nonexistent.) An easy rule of thumb for protecting a
semiconductor is...your thumb. Seriously, mount the diode block, wire it up
to supply and load, and power it up, keeping one hand on the switch and a
finger or thumb on the diode block. If you can keep your appendage on the
diode without getting burned, it isn't getting too hot. Most semiconductors
are rated at somewhere between 80C & 100C, which is much more than a normal
human can stand touching their skin.
If you're running a single 5A load through a 50A Shottky, you probably
don't need to worry too much about thermal damage.
Charlie
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: mystery relay |
Search internet for "40 amp automotive relay".
You can buy relays at auto parts stores.
Some relays come with a built-in arc suppression diode,
but they are not easy to find.
So, install a diode across the relay coil with the banded end towards positive.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=494963#494963
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: New role for the E-Bus? |
The 30 amp fuse protects the wire running from the bus to the circuit breaker.
It replaces the fuselink in older Z figures. If the over-volt module shorts out
the circuit, hopefully the 5 amp circuit breaker will trip, but the fuse will not
blow. A smaller value fuse might blow before the circuit breaker trips.
-
One reason for using a relay is for remote control. A relay can shut off the
electrical power close to the source instead of running an always hot wire into
the cockpit.
Shutting off power at the source might prevent sparks after a forced landing.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=494964#494964
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: mystery relay |
user9253 wrote:
> Search internet for "40 amp automotive relay".
>
Thanks Joe,
I was expecting a 40 A relay to be labeled S8009-1, that's what led me to call
it Mystery Relay. Z-02, which is preliminary, implies the relay is able to carry
enough current to blow a MANL 30; I wasn't sure a 40 A relay would do that.
I gather a 40 A automotive relay is TE connectivity 1432791-1 or similar.
--------
John Bright, RV-6A, at FWF, O-360, dual SDSEFI EM-5-F
Dual batt dual alt SDS dual EM-5-F but considering a single batt design.
john_s_bright@yahoo.com, Newport News, Va
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=494966#494966
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|