| T O P I C R E V I E W |
| richardc |
Posted - Feb 16 2012 : 04:31:32 AM
Hi - Very new to this subject so apologies for such a basic question but here goes-
I am currently building a circuit from this website which is a timed relay. Basically its a 555 timer IC used to control the time interval (on time) of a relay.
The circuit diagram aaron publishes indicates 12v which is fine - except that I am trying to install this timer inside a piece of existing equipment which seems to run at just 3v off its own internal transformer.
- so presumably I need to run the new timer off its own little battery - or install a whole power supply for it.
Just to complicate the issue, the existing transformer inside the unit is really poor construction ( made v cheaply in india ) and really I ought to be replacing that as well.
Is there an easy way to install a new power supply that can serve both voltages 12v and 3v ??
Thanks a lot!!
Richard |
| 3 L A T E S T R E P L I E S (Newest First) |
| pebe |
Posted - Feb 20 2012 : 11:56:48 AM
You can use an LMC555 CMOS timer. It is specified to work down to 1.5V supply.
The timing components remain the same - whatever the voltage.
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| richardc |
Posted - Feb 20 2012 : 10:43:44 AM
Hi -
I have read about a lower voltage version of the 555 but if I use that, wont I need to change the values of the capacitors etc to keep the same time interval range?
I think it may be best use a 12v supply and also use this to serve the other 3v electronics by adding some componentry. Any ideas where I can find out how to do this?
Thanks a lot.
Richard |
| Aaron Cake |
Posted - Feb 18 2012 : 10:53:20 AM
There may be a low voltage version of the 555 timer. Check the datasheet.
If not, maybe all you need is a simple RC network? |
