@eric sir..
i want to drive that load cell circuit with standard and fixed 24 volt..
but load cell required 10 volt and the operating voltage for circuit is 10 volt ,..
so i have convert that 24 volt to 10 volt by means of lm317t.
i have attached that circuit file..
the circuit performed well up to 15 volt..but when i increased voltage further towards 24 volt to test... lm317t get heated very rapidly but that time o/p is constant 10volt..
i dont understand why this happening ..plz find the attachments and suggest me the solution ...

 

hi,
How much current is the LM317 supplying to the load.?
The dissipation in the LM317 is Wattage= [Vin-Vreg]/Iload if that exceeds the datasheet rating then you will require a heat sink on the LM317
E
EDIT:
Look at this Tool I did sometime ago.
http://www.electro-tech-online.com/tools/LM317V2.php

 

hi sir
in that load cell functioning properly .but during testing it on site we got one natural problem.
on different floor(elevator) we got different o/p for the load cell
on ground floor at comparator stage reference cross by load cell is earlier than on corresponding up floor .
any solution for this if u r having plz help.

 

and also
i want to design uninterrupted power supply (ups) for the rating of 5 kva
i want the circuit solution
or any other site where i get circuit dig or idea to design plz do tell me.

 

in that load cell functioning properly .but during testing it on site we got one natural problem.
on different floor(elevator) we got different o/p for the load cell
on ground floor at comparator stage reference cross by load cell is earlier than on corresponding up floor .
any solution for this if u r having plz help.

hi,
Have you considered the weight of the hoist cables that maybe acting on the load cells.?
E

 

right sir
but
so there is problem with the circuit at all the time
it will give different o/p at different floors
what i was thinking to use all the comparator of lm339
set them on different floor
and cutoff them on perticuler floor

 

Please post details of the 'differences' that you see from floor to floor also where the L/C is located.

 

oh....i havent check for it
ok i will take reading for that and will text u sir

 

hi eric sir..good afternoon
sir,
i want to designe simple circuit like inverter
where in when i give 24 volt input to the input terminal then i should get pure zero volt at o/p
so i can drive my common cathode seven seg display.
i was trying this by using optocoupler
bt i dnt get exact solution
i will attached file for that
so plz give me correction or if you have any idea do suggest
thanks
regards
Nikhil

 

basic idea of circuit

 

here in this i need 7 relay for 7 differernt 24 volt from field
so i want to replace relay
plz give me the solution that how can it is possible with minimum circuitry

 

hi,
If I understand you correctly, you have signal lines that can be at 24V or 0V and you want to use these lines to drive a CC [ common cathode 7 segment LED].?

You can use a transistor to pull a CC LED down to close 0V. Use a suitable value resistor in the Base of the transistor to the the 24v/0v signal line.
For example: if the LED has all 7 segments 'lit' and each segment current is say 10mA, thats 70mA total.
Use a 2N2222 transistor, with a 70mA/10 , 7mA Base current, say a 3K3 Base resistor.

Note: you will need a current limiting resistor for each LED segment from the LED supply/drive.

E

 

here i have attached file as per your design and i get proper o/p
there are two condition when switch is press and and not press
bt sir as per my application i need to use high collector current transistor
because the current rating for 2n2222 is 800ma
i am going to use this circuit in elevator application
so on each floor due no of seven seg display increse with the floor,so the current rating need to have increse
so is it suitable to use power transistor
if then plz sir tell me name for the same
Thanks
regards
nikhil

 

plz find the attachments

Thanks
regards
Nikhil

 

hi Nikhil,
A couple of questions or so.
What will the 7 segment LED on each floor be displaying.????
How many 7 segs LEDs will be used on each floor.?
Have you considered the voltage losses in a cable 100 floors in length.??
Eric

 

What will the 7 segment LED on each floor be displaying.????
ans= the corresponding seg will glow where the lift is halt.
means if lift is at 9th floor then on each floor there will 9 will be shown on each floor.
How many 7 segs LEDs will be used on each floor.?
ans=only one 7 seg on each floor.
Have you considered the voltage losses in a cable 100 floors in length.??
ans=no sir i havent yet consider voltage loss.

 

hi,
If there is only one LED digit on each floor, how can the display show 10 thru 20, on a 20 level building.?

Assume 1 Amp for all the LEDs CC connection, I would use a 2 to 3 Amp [ Id current] N MOSFET, you have a 0v/24V switched Gate source voltage.
A simple resistive divider could reduce that to say 0v/10V.

E
Corrected floor level count.

 

sorry my mistake
there are two seven seg display on each floor
ok sir iwill prefer that
as i am not having experience on mosfet circuit,can u plz tell me which one should i use which is also cost effective and easily available(i have attached list for them,i am also seaching for suitable,)
Thanks and Regards
NIkhil.s

 

Hi,
I would suggest a 'thru hole' T0220 N MOSFET case style.
Drain voltage range 30V or higher.
Drain current range 3A or higher .
Rds ON, less than 0.1 ohm
Vgs threshold, 3V thru 12V.

There are many types that would suit your application.
E

 

EDIT: removed post that belonged in a different thread.