Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.




Lock him up!
10965 posts

Uber Geek

Lifetime subscriber

# 180978 28-Sep-2015 15:10
Send private message

Where to post this? Not sure which forum fits, hopefully a mod will fix it.

I bought a little automotive digital clock with illuminated display (red segments). It has + and - power leads, a little setting button on separate leads, and a compartment for a 3-volt button battery, but no installation instructions at all. I am fairly handy with this sort of thing, but not sure how to proceed in this case and the clock was sold (Ebay) with no specs of any kind. 

I figured there would be some kind of dual power connection as with radios to keep the clock chip going when the car is not running with a circuit through the ignition switch to light up the display. This does not seem to be the case. Although the clock is advertised as being suitable for cars and motorcycles, there is only the one power connection with the unexplained battery compartment. 

If I hook the power through the switch, the clock loses its setting when the switch is off (unless the button battery has something to do with this). The only other option is to connect it directly to the car battery, meaning the display is always on. It is LED but will this not drain the battery over time? The display is pretty bright and there are several segments.

I am not sure how to proceed. Does anyone know the correct way to do this?
 




I don't think there is ever a bad time to talk about how absurd war is, how old men make decisions and young people die. - George Clooney
 


Create new topic
3344 posts

Uber Geek

Trusted
Vocus

  # 1395839 28-Sep-2015 15:16
Send private message

Fit a 3v battery in the compartment and you should be sweet

gzt

10985 posts

Uber Geek


  # 1395848 28-Sep-2015 15:26
Send private message

3v battery holds the time when ignition power is off.

 
 
 
 




Lock him up!
10965 posts

Uber Geek

Lifetime subscriber

  # 1395884 28-Sep-2015 16:23
Send private message

That makes sense. Thanks.





I don't think there is ever a bad time to talk about how absurd war is, how old men make decisions and young people die. - George Clooney
 


Banana?
4880 posts

Uber Geek

Subscriber

  # 1395887 28-Sep-2015 16:27
Send private message

-ve lead to Earth (Black), +ve lead to Ignition (usually Red). You should be able to hook into the stereo loom?

Be interesting to see how long the battery lasts as it will spend more time on battery than it will on car power.



Lock him up!
10965 posts

Uber Geek

Lifetime subscriber

  # 1396064 28-Sep-2015 20:26
Send private message

I'm wondering about that. Makes it difficult to permanently install the clock where I wanted to since I don't want to have to disassemble the dash every time the battery needs replacing. What if I make a voltage divider (3 volts) and solder a connection to the terminals of the button battery holder and run that directly to the car battery?





I don't think there is ever a bad time to talk about how absurd war is, how old men make decisions and young people die. - George Clooney
 


gzt

10985 posts

Uber Geek


  # 1396112 28-Sep-2015 21:12
Send private message

Does it support daylight saving? ; )



Lock him up!
10965 posts

Uber Geek

Lifetime subscriber

  # 1396126 28-Sep-2015 21:33
Send private message

I doubt it but the external button makes the time easy to change. The same can't be said for the battery.





I don't think there is ever a bad time to talk about how absurd war is, how old men make decisions and young people die. - George Clooney
 


 
 
 
 


3885 posts

Uber Geek

Subscriber

  # 1396200 28-Sep-2015 23:03

Just get one of these batteries http://www.jaycar.co.nz/Power-Products-Electrical/Storage-Batteries/Cordless-Phone-%26-Specialty/Lithium-AXIAL-AA-3-6v/p/SB1775 It will probably outlast the clock. Or if you really want to get rid of the battery. Get a 3.3V voltage regulator. http://www.jaycar.co.nz/PRODUCTS/Active-Components/Regulators/Low-Dropout/LM3940-Low-Dropout-Regulator/p/ZV1565 just wire up 2x 0.1uF capacitors between the input pin and ground and the output pin and ground. And wire an LED in series with a 1Kohm resistor on the output as well. just to provide a little more load on the regulator. As the clock mem backup load will be too small.







Lock him up!
10965 posts

Uber Geek

Lifetime subscriber

  # 1396318 29-Sep-2015 08:55
Send private message

OK thanks for that. It is really helpful.





I don't think there is ever a bad time to talk about how absurd war is, how old men make decisions and young people die. - George Clooney
 


Create new topic



Twitter and LinkedIn »



Follow us to receive Twitter updates when new discussions are posted in our forums:



Follow us to receive Twitter updates when news items and blogs are posted in our frontpage:



Follow us to receive Twitter updates when tech item prices are listed in our price comparison site:





News »

Intel introduces cryogenic control chip to enable quantum computers
Posted 10-Dec-2019 21:32


Vodafone 5G service live in four cities
Posted 10-Dec-2019 08:30


Samsung Galaxy Fold now available in New Zealand
Posted 6-Dec-2019 00:01


NZ company oDocs awarded US$ 100,000 Dubai World Expo grant
Posted 5-Dec-2019 16:00


New Zealand Rugby Selects AWS-Powered Analytics for Deeper Game Insights
Posted 5-Dec-2019 11:33


IMAGR and Farro bring checkout-less supermarket shopping to New Zealand
Posted 5-Dec-2019 09:07


Wellington Airport becomes first 5G connected airport in the country
Posted 3-Dec-2019 08:42


MetService secures Al Jazeera as a new weather client
Posted 28-Nov-2019 09:40


NZ a top 10 connected nation with stage one of ultra-fast broadband roll-out completed
Posted 24-Nov-2019 14:15


Microsoft Translator understands te reo Māori
Posted 22-Nov-2019 08:46


Chorus to launch Hyperfibre service
Posted 18-Nov-2019 15:00


Microsoft launches first Experience Center worldwide for Asia Pacific in Singapore
Posted 13-Nov-2019 13:08


Disney+ comes to LG Smart TVs
Posted 13-Nov-2019 12:55


Spark launches new wireless broadband "Unplan Metro"
Posted 11-Nov-2019 08:19


Malwarebytes overhauls flagship product with new UI, faster engine and lighter footprint
Posted 6-Nov-2019 11:48



Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.


Support Geekzone »

Our community of supporters help make Geekzone possible. Click the button below to join them.

Support Geezone on PressPatron



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.

Alternatively, you can receive a daily email with Geekzone updates.