• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

memory

arivel

Member
Hello. do you recommend me?
I have to memorize the outputs of the binary counter UP / DOWN 40193 (when the power supply returns, the memory must update the counter), I do not want to use a buffer battery or even a microcontroller.
I would like to use a very simple and easy to implement non-volatile memory.
 

Beau Schwabe

Active Member
Why not a micro controller? I could program something for you that would do exactly what you want.

PM me and I can give you more details
 

Diver300

Well-Known Member
Most Helpful Member
A CD40193 will consume less than 100 nA and will work from 3 - 18 V. A supercapacitor of 0.1 F, charged to 5 V, will last the CD40193 for about a month. I think that in practice it will be more. The time will most likely depend on the leakage and could be worse in damp conditions.

I would agree that you need a microcontroller to run NV memory, so you might as well have a microcontroller with built-in NV memory.
 

Ian Rogers

User Extraordinaire
Forum Supporter
Most Helpful Member
Not all NV memories are un-useable without micro's..

We used to use battery backed parallel memory chips ( still do ) MK48Z02.. if it was connected to the counter it could work... I know you said "no battery" but these are built in..
 

gophert

Well-Known Member
Most Helpful Member
You could use a cd4508 (dual 4-bit latch). The part takes Nano-amps when outputs are tri-stated to high impedance (not input or output).
3-AA batteries will last More than 10-years or use your existing batteries if it is a battery operated device.
 

Beau Schwabe

Active Member
A micro in sleep mode generating an interrupt on change only takes about 50nA and will work down to 1.8V in Static RAM mode (unlimited writes) .... NV RAM mode (limited writes - 10,000) and retain the data for up to 40 years.
 

gophert

Well-Known Member
Most Helpful Member
But then the OP needs a programmer, IDE and programming lessons. A low power latch only requires a soldering iron.
 

gophert

Well-Known Member
Most Helpful Member
What does "Schwabe " mean in English? Smeller of business opportunities?
 

arivel

Member
Bye and thanks for the answers .
is it possible to use an inductance with a ferrite core and a small HALL latch effect sensor in order to exploit the magnetic hysteresis?.
 

kubeek

Well-Known Member
Most Helpful Member
you mean a ferrite core memory? sure it is possible, but the read and write circuits are a bit complicated. And you need a suitable core material.
 

gophert

Well-Known Member
Most Helpful Member
Bye and thanks for the answers .
is it possible to use an inductance with a ferrite core and a small HALL latch effect sensor in order to exploit the magnetic hysteresis?.
A latching relay is essentially the mechanical equivalents of a latching hall sensor.
 

AnalogKid

Well-Known Member
Most Helpful Member
I like the magnetic core question. There used to be small core memories mounted in DIP carrier devices. These have morphed into today's MRAM components.

What are the world's smallest (in data size) MRAM and flash memory devices? Nybble- or byte-wide?


ak
 
Last edited:

arivel

Member
A latching relay is essentially the mechanical equivalents of a latching hall sensor.
for what I have to do, the use of bistable relays is already foreseen, directly controlled by the outputs of the count 40193.
then instead of adding others can I open the casing of those already present and apply the HALL sensor near the coil?
alternatively also a REED contact?
 

gophert

Well-Known Member
Most Helpful Member
for what I have to do, the use of bistable relays is already foreseen, directly controlled by the outputs of the count 40193.
then instead of adding others can I open the casing of those already present and apply the HALL sensor near the coil?
alternatively also a REED contact?
No, a latched relay changes state with start of each pulse and don't care if you continue to power or cut power. Then you would need to read the state of each relay switch (which is attached to a pull-up resistor on one end and ground on the other. You would need to energize the switched circuit and read the status of each latch relay before you apply power to the coil because the coil will trigger to the next state when you re-energize it (unless you have a way to keep power on part of your circuit).
 

arivel

Member
No, a latched relay changes state with start of each pulse and don't care if you continue to power or cut power. Then you would need to read the state of each relay switch (which is attached to a pull-up resistor on one end and ground on the other. You would need to energize the switched circuit and read the status of each latch relay before you apply power to the coil because the coil will trigger to the next state when you re-energize it (unless you have a way to keep power on part of your circuit).
I don't understand your answer.
I've been doing research and questions for some time to understand something about bistables. that's why I asked the question here:
there are apparently three types:
1 coil 2 terminals, 2 coils 3 terminals, 2 coils 4 terminals. then there is a fourth type, the polarized ones that make use of a permanent magnet.
then there is the step-by-step and the REED one.
until yesterday I was convinced that all types, excluding that step by step, were polarized.
instead today I read this link:
on page 2 under the title Remanence relays. therefore it seems that the core remains magnetized even when the power supply is removed. I don't know if it works the same for REEDs.
therefore, when the power supply returns, the HALL sensor reads the status of the core. however, if the magnetic flux does not change direction, the HALL sensor does not change state and is therefore unusable.
what type are you referring to?
 

gophert

Well-Known Member
Most Helpful Member
what type are you referring to?
Mechanical Latching Relays...
(like a push-button that is not of the momentary type)

Mechanical latching relays
As opposed to a magnetic latching system, a mechanical latching relay uses a physical locking mechanism to hold the armature in place against the contact in the last position it was moved to. Electromechanical relays bring various pros and cons into play:

  • They tend to feature larger, bulkier contacts than electromagnetic versions, and are therefore less flexible units in terms of space requirements
  • Mechanical latching relays tend to be better at coping with unexpected surge currents
  • Speed of switching is limited due to the extent of mechanical movement required, making them unsuitable for some applications
  • The lifespan of mechanical latching relays is typically somewhat shorter than for magnetic versions in terms of overall number of actuations
  • However, current size is an equally important consideration in terms of overall longevity for any relay switch
    • The projected lifetime of mechanical relays under higher loads will often decrease much more slowly over time than for magnetic reed versions
    • Its contacts will be less prone to weakening during thermal cycling than an electromagnetic latching relay
 

arivel

Member
you have to understand how the coil core works.
I thought of two possible ways.
1) inversion of the polarity of the magnetic flux
2) presence of magnetic flux - absence of magnetic flux.
 

Latest threads

EE World Online Articles

Loading
Top