Circuitry for striking clock.

Thread Starter

RMHC

Joined Nov 13, 2019
45
Oops, neglected to look at that. :oops:

Here's one that goes to 12V max input.
That looks good, it has 50mA O/P load which is plenty good for the clockmotor. Datasheet says I/P and O/P decoupling is required, 0.1mF minimum. The solenoid is 6v at 600mA, is that OK for the IRF9410? Cheers. RMHC.
 

Thread Starter

RMHC

Joined Nov 13, 2019
45
Great.
Let us know how it works.
Hi, Sorry to bother you but the IRF 9410 is a tiny package not really suitable for hand work. Is there a larger package version suitable for normal PCB work? I have looked in Mouser but don't really know what to look for! Cheers RMHC.
 

Thread Starter

RMHC

Joined Nov 13, 2019
45
One of these should work.
I looked for N-MOSFET, logic-level, through hole devices.
Hi Mr crutschow,
I Have the chime cct. dummied up on a test board and when I simulate the hour chime the solenoid operates just fine. The problem I have is that when the contacts on the clock pulse on the hour the solenoid does not operate. The contacts are definitely closing for a very short time as the mechanism releases on the hour but apparently the pulse is too short. Is that possible or am I full of prune juice! I would have thought that the mosfet would have 'seen' a milli-second pulse and responded to it. I have tried reducing R3 to 4.7K and changing C1 but there is no change. Do you have any suggestions to improve the sensitivity of the circuit???? Many thanks for any help. RMHC.clock striking cct2.jpg
 

crutschow

Joined Mar 14, 2008
23,813
The circuit, as is, needs the contacts to close for at least 100ms.

Try reducing the value of R3 to about 100Ω, and add a 1μF capacitor across R2.
The circuit should then respond to a shorter contact closure.
 
Last edited:

Thread Starter

RMHC

Joined Nov 13, 2019
45
The circuit, as is, needs the contacts to close for at least 100ms.

Try reducing the value of R3 to about 100Ω, and add a 1μF capacitor across R2.
The circuit should then respond to a shorter contact closure.
Many thanks. I will re-evaluate it on Friday. RMHC.
 

Thread Starter

RMHC

Joined Nov 13, 2019
45
One of these should work.
I looked for N-MOSFET, logic-level, through hole devices.
Hi Mr crutschow,
I Have the chime cct. dummied up on a test board and when I simulate the hour chime the solenoid operates just fine. The problem I have is that when the contacts on the clock pulse on the hour the solenoid does not operate. The contacts are definitely closing for a very short time as the mechanism releases on the hour but apparently the pulse is too short. Is that possible or am I full of prune juice! I would have thought that the mosfet would have 'seen' a milli-second pulse and responded to it. I have tried reducing R3 to 4.7K and changing C1 but there is no change. Do you have any suggestions to improve the sensitivity of the circuit???? Many thanks for any help. RMHCView attachment 193270

The circuit, as is, needs the contacts to close for at least 100ms.

Try reducing the value of R3 to about 100Ω, and add a 1μF capacitor across R2.
The circuit should then respond to a shorter contact closure.
Hi, I hope you had a good thanksgiving yesterday. I have made the 2 changes you suggested and the solenoid now activates albeit a little sluggishly I think. If I put the 6v. directly across the solenoid coil it is pretty lively, but less so when the M1 mosfet triggers it. Can this be improved? By the way I am using small polarised caps because they are all I have. Is that OK or should I use a disc ceramic for C1? Many thanks for any more suggestions. RMHC.clock striking cct2.jpg
 

crutschow

Joined Mar 14, 2008
23,813
If I put the 6v. directly across the solenoid coil it is pretty lively, but less so when the M1 mosfet triggers it. Can this be improved?
You could try increasing the value of C1 and/or C4.

If the contact closure time of the clock switch is short than you could just eliminate C1 and R1.
By the way I am using small polarised caps because they are all I have. Is that OK or should I use a disc ceramic for C1? Many thanks for any more suggestions.
A polarized cap is okay for C1 as long as the (+) terminal goes to the input (connection to C4).
You didn't show the capacitor polarity on the schematic, which you should for any polarized capacitors.
 

Thread Starter

RMHC

Joined Nov 13, 2019
45
You could try increasing the value of C1 and/or C4.

If the contact closure time of the clock switch is short than you could just eliminate C1 and R1.
A polarized cap is okay for C1 as long as the (+) terminal goes to the input (connection to C4).
You didn't show the capacitor polarity on the schematic, which you should for any polarized capacitors.
Thanks Mr C. I will try both those suggestions also I need to minimise arcing at the clock contacts which are VERY delicate..
As always many thanks and I look forward to your next helper. RMHC.
 

Thread Starter

RMHC

Joined Nov 13, 2019
45
Hi Crutschow,
The chiming cct. works well as you designed it. Many thanks. The only problem now is the power supply cct I got from the maker of the LDO- LD1117V. It has a no load current of 10mA which seems excessive so I have temporarily tapped into the 6v battery for the 1.5v clock supply. I hope to find a better way to obtain the 1.5v clock supply. I really appreciate your help with this project. RMHC.
 

Thread Starter

RMHC

Joined Nov 13, 2019
45
Why did you change the regulator from the one I suggested?
Hi Mr C,
The reason I changed the reg. was because the one you suggested
MC78LC15NTRG was super tiny, as in micro....not suitable for home use. It is not made in a TO 220 package apparently.
It has a quiescent current of about 1uA which is ideal for good battery life. If you find one in a larger format with similar specs i would welcome it... Cheers RMHC.
 
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