hi,

ive been looking at this project

http://www.allaboutcircuits.com/vol_6/chpt_7/3.html

is it the most power effective way of making a latch circuit, my circuit is run off a 6v lead acid battery and battery life is very important

thanks

 

It's one method of making a latching circuit. What are you latching? Why are you latching it?

 

It's one method of making a latching circuit. What are you latching? Why are you latching it?

it goes to a digital input on a gsm modem that needs to be held high until it is reset using the reset input. battery consumption is also an important factor. i like the circuit listed because it has a reset and alarm led, i would like to use a bi coloured led, flashing say once every 30 seconds green if reset and red every 30 seconds of in 'alarm' condition.

thanks
fred

 

Use a RS latch IC of the CMOS technology to reduce power consumption. CMOS consume less power when used in low frequency applications compared to TTL.

 

Use a RS latch IC of the CMOS technology to reduce power consumption. CMOS consume less power when used in low frequency applications compared to TTL.

would the same ciruit be suitable with a different ic?

 

Yes, if the ic has the same function.

 

Hello,

Here are two lists from the wiki.
1) Cmos 40XX series : http://en.wikipedia.org/wiki/List_of_4000_series_integrated_circuits
2) TTL 74XX series : http://en.wikipedia.org/wiki/List_of_7400_series_integrated_circuits

Here you can compare IC functions between Cmos and TTL.

Greetings,
Bertus

 

If you have a digital TTL input, then sending 6 volts is very risky ( too high). I suggest to place a resistor devider so that you will send to the input no more than 5 volts (max)

Alberto

is that like a potential divider... bit new to this...sorry!

 

Hello,

Normal TTL (74XX) and HCT (74HCTXX) will work from 4.75 to 5.25 Volts.
Cmos (40XX) will work from 3 to 15 Volts.
HC mos (74HCXX or 40HCXX) will work from 3 to 6 Volts.

Greetings,
Bertus

 

Hello,

Normal TTL (74XX) and HCT (74HCTXX) will work from 4.75 to 5.25 Volts.
Cmos (40XX) will work from 3 to 15 Volts.
HC mos (74HCXX or 40HCXX) will work from 3 to 6 Volts.

Greetings,
Bertus

looks like i need to contact the manufactures and confirm what the inputs are and their ratings!

 

Hello,

For an overview of digital stuff, take a look at these pages.
http://www.educypedia.be/electronics/digitaltechnology.htm

Digital electronics:
Arithmetic circuits D/A-A/D converters Number systems Codes and decoders Flip flops Technology Counters and registers General overview Technology-CMOS Digital logic Memories Technology-TTL Timers and oscillators

Greetings,
Bertus