Dave M wrote:
John Robertson wrote:
On 2017/08/26 7:52 PM, Dave M wrote:
John Robertson wrote:
I am replacing an old TRIAC that is used for a solenoid driver
driven by a photo-flash (I have dozens of these in my classic rifle
gallery) and I can't find anything on line about this particular
device. I know it is 400V, 3A, and is in a TO-11 like metal can
however what I can't find is the Gate current. This is a sensitive
gate TRIAC and I suspect it is either a 3MA or a 10MA device, but would
like a copy of the original TECCOR specs to be sure that the
replacement I am using is close enough to the original for long
term reliability. This is being controlled by a device called a
Vactrol - VTL2C3, and I have several dozen of these controllers
that eventually need upgrading. So, if anyone has a TECCOR
Electronics Inc. manual lying around from
the early 70s and can scan me the page(s) on the Q4003M3 that would
be great. I have found sheets online for other flavours of the
Q4003 series, but just not the Mx version.

Thanks!

John :-#)#


I just need to sit down and spend a couple of hours on this project.

Thanks,

John :-#)#


Seems like a triggered one-shot 555 timer circuit would be a natural
solution to this problem. Circuit values are easily calculated for
the required delay, and the 555 can drive the triac directly or
through an optocoupler.

What's the normal ON time for the existing circuit? Do you use only
the photocell input or in conjunction with the reed switch input?

Dave M

This is a basic circuit for a 555 monostable. Circuit values easily
determined from one-shot requirements.


Please view in a fixed-width font such as Courier.

+Vcc
|
|
| AC
+--------------+---------------+-------+ +--
| | | | |
| | | +-+-+ |
+-+-+ +-+-+ | | | +---+
| | | | | | | | |
| | | | | |R3 | | |MT1
|R1 | | | | | | | +-+-+
| | |R2 | | | | +--------+ | | |
| | | | +----+ +-+-+ | | | | |
| | | | | | +---+ +--+ | |Triac
+-+-+ +-+-+ +----+----+---+ | | | |
| | | 4 8 | | Opto | +-+G |
| | | | | Triac | | +-+-+
+--------------------+2 | | Driver | | |MT2
| | | | | | | |
| | | +-------+ +--+ |
| | | | | | |
| | | | +--------+ +--
+-+-+ +-----+6 | Load
| | | | NE555 |
| | | | |
| |Photo +-----+7 |
| |Cell | | |
| | | | |
+-+-+ | | |
| +-+-+ | |
| | | | |
--+-- | | | 5 1 |
Gnd |C1 | +----+-----+--+
| | | |
| | +-+-+ |
+-+-+ | | |
| |C2 | |
| | | |
--+-- | | |
Gnd +-+-+ |
| |
| |
+-----+
|
|
--+--
Gnd

Dave M