DIY Tach Filter - Assembly of Parts (Circuit Validation)
11-18-2005, 12:48 AM
#1
Le Mans Master
Thread Starter
DIY Tach Filter - Assembly of Parts (Circuit Validation)
Can someone confirm that I have assembled the
parts as indicated by the circuit diagram.
It is a simple layout but I don't do this often
enough and it isn't working as expected.
Thanks,
Ken R.
parts as indicated by the circuit diagram.
It is a simple layout but I don't do this often
enough and it isn't working as expected.
Thanks,
Ken R.
11-18-2005, 01:01 AM
#2
Safety Car
Providing you have the proper valued caps and resistors in the correct location what you have shown is the same circuit configuration as the pic. What is not indicated in the drawing are the cap or resistor values. and I can not see the cap values in the pic of filter.
11-18-2005, 01:12 AM
#3
Le Mans Master
Thread Starter
.10 MFD between the 5.6 K and the 10 K.
100 PF after the 10K.
Markings (engage bifocals)
435 AFO / 104 E1M
A2R 101 / JAX 410
.
100 PF after the 10K.
Markings (engage bifocals)
435 AFO / 104 E1M
A2R 101 / JAX 410
.
Last edited by Slalom4me; 11-18-2005 at 01:19 AM.
11-18-2005, 01:45 PM
#5
Le Mans Master
Thread Starter
To provide a clean tach signal from an OEM HEI in an '89 C4.
The signal from the 'Tach' terminal on the cap is v-dirty and
provides inaccurate readings.
.
The signal from the 'Tach' terminal on the cap is v-dirty and
provides inaccurate readings.
.
11-18-2005, 01:53 PM
#6
Le Mans Master
Thread Starter
Like this one
and essentially the same as this one
In fact, if anyone knows what the difference is between the
examples above - besides packaging - then this might explain
why the parts I'm using (74-82 design) are not working as
expected on an '89.
.
and essentially the same as this one
In fact, if anyone knows what the difference is between the
examples above - besides packaging - then this might explain
why the parts I'm using (74-82 design) are not working as
expected on an '89.
.
11-18-2005, 04:51 PM
#7
Le Mans Master
Originally Posted by Slalom4me
To provide a clean tach signal from an OEM HEI in an '89 C4.
The signal from the 'Tach' terminal on the cap is v-dirty and
provides inaccurate readings.
.
The signal from the 'Tach' terminal on the cap is v-dirty and
provides inaccurate readings.
.
heh.. got that part
...but what do you need the filtered tach signal for?
11-18-2005, 11:19 PM
#9
Le Mans Master
Thread Starter
Originally Posted by scott_fx
heh.. got that part ...but what do you need the filtered tach signal for?
...but what do you need the filtered tach signal for?
In addition to the GPS, lat/long accelerometers, RPM, MPH, track
mapping and the other default functions, I also have the WB O2
module. They have just released several additional modules and
I expect to be adding to my system, soon.
Pretty nice unit. Very scalable and extensible - yet economical
compared to other units with similar capabilities.
.
11-18-2005, 11:25 PM
#10
Le Mans Master
Thread Starter
Originally Posted by Bluevette85
Here's a diagram I found:
You might try ceramic disc capacitors.
You might try ceramic disc capacitors.
The circuit in the diagram looks to be the same as the one I've
based my work on.
Thanks.
.
11-19-2005, 12:51 AM
#12
Le Mans Master
Thread Starter
Any chance I've got the wrong capacitor?
There is supposed to be a 100 PF cap after the 10K resistor. However,
the vendor (the entire industry?) doesn't make it so simple as browsing
the capacitor aisle for a package marked '100 PF'.
The package denotes 200 V 0.0001 uF. According to some information
I later found, this translates to 100 pF.
However, the markings on the caps are 'A2R 101' on one side and
'JAX 410' on the other. According to my information, a 100 pF should
be marked with a '110' code (who comes up with this stuff ???)
- mine appears to be marked '101'
So, is this a case of mislabeled parts ?
.
There is supposed to be a 100 PF cap after the 10K resistor. However,
the vendor (the entire industry?) doesn't make it so simple as browsing
the capacitor aisle for a package marked '100 PF'.
The package denotes 200 V 0.0001 uF. According to some information
I later found, this translates to 100 pF.
However, the markings on the caps are 'A2R 101' on one side and
'JAX 410' on the other. According to my information, a 100 pF should
be marked with a '110' code (who comes up with this stuff ???)
- mine appears to be marked '101'
So, is this a case of mislabeled parts ?
.
11-19-2005, 01:13 AM
#13
Le Mans Master
Thread Starter
Hmmm,
Code 101 means 10 with 1 more zero or 100 pF
Code 110 means 11 with no more zeros or 11 pF (Now this conflicts
with a Philmore-Datak chart)
.
Code 101 means 10 with 1 more zero or 100 pF
Code 110 means 11 with no more zeros or 11 pF (Now this conflicts
with a Philmore-Datak chart)
.
11-19-2005, 01:32 AM
#14
Team Owner
Member Since: Mar 2001
Location: Cincinnati, Oh USA
Posts: 53,935
Likes: 0
Received 26 Likes
on
23 Posts
The last digit is the number of zeros, so 101 means 100 pF. A 0.1 MF(also 0.1 uF) capacitor should be marked, 105. You may not have a 0.1 uF capacitor. Find someone that has a capacitance meter and measure the part, or buy a capacitor that is definetely 0.1 uF.
Last edited by jfb; 11-19-2005 at 10:48 AM.
11-19-2005, 10:50 AM
#15
Le Mans Master
Thread Starter
Originally Posted by jfb
A 0.1 mF (also 0.1 uF) capacitor should be marked, 105.
Several references I've seen show an 0.1 mF capacitor marked as 104.
Here is one instance
The same references show a 1.0 mF marked as 105.
Regards,
Ken R.
.
