Yes, that circuit is correct.

And here is a little tip...

If you leave pin 9 open, you can use it as a lamp test by bringing it low.

 

Looks like it. I like how you eliminated the unnecessary wire crossings.

It would be nice if you moved the component designators for Nano and IC1 closer to their symbols.

Does fritzing have a print option? Colored schematics seem a bit amateurish to me.

HI Dennis
Yes I'll try that. It does i think, at some point I'm going to try and a make a PCB with it, just a bit of fun to see how it works. My idea is to have it either controlled by a motion sensor or a button, but I'll have to work out have to do that, I'll see if i can use the print option.

 

Yes, that circuit is correct.

And here is a little tip...

If you leave pin 9 open, you can use it as a lamp test by bringing it low.

Brill, im chuffed with that! good tip too!

Now to tackle the sketch/code problem I have

 

Hello,

What is the base if the lamps?
There might be leds available with the same base.
https://lightadviser.com/light-bulb-base-chart/

Bertus

 

Hello,

What is the base if the lamps?
There might be leds available with the same base.
https://lightadviser.com/light-bulb-base-chart/

Bertus

GI 738 Midget Miniature Bulbs 6mm 6.3v 0.04A Flange SX6s 5 Lumens OM0297

 

Hello,

Would this fit:
https://www.bulbtown.com/T1_3_4_6V_28V_WHITE_L_E_D_MINIATURE_GROOVE_BASE_p/l8041.htm

Bertus

 

And only 119$ for the lot...what a bargain.

Yea direct replacements are very costly, as shown in my link in the second post.

 

I have changed the lamps to 6.3 V O.2mA.

Confused on the bulb's current. Is that 0.2mA, 2mA?

 

Hello,

These seem to have a better price, but are 12 Volts:
https://www.ledlight.com/t1_3-4_mid_groove_base_led_bulb_12v.aspx

Bertus

 

Confused on the bulb's current. Is that 0.2mA, 2mA?

APologies, they are 04A

 

And only 119$ for the lot...what a bargain.

Yea direct replacements are very costly, as shown in my link in the second post.

Yes thats why i opted for these bulbs i picked up for £12 for 20 - leds woudl be greta but so expensive to replace these bulbs

 

APologies, they are 04A

So 40mA, like the originals just lower voltage. You will want to wire them in parallel not series for maximum brightness and use a 6V supply. That gives you 160mA. The circuit you have using the ULN2003A should work fine. Those can handle 500mA. Not sure what the inrush current is for those bulbs. If you want to know, just measure the cold temperature resistance across the bulb. When hot it is 6.3V/0.04A or 157 ohms. What is the cold reading with a DMM? This is important because it determines the inrush current for the bulb. If it is less than 6.3V/125mA that is 50 ohms, you will need to either consider a different driver part or add some sort of current limitation circuit. Keep in mind these will only have 1/4 the brightness over the original 28V ones, being they are only using 1/4 the power.

 

So 40mA, like the originals just lower voltage. You will want to wire them in parallel not series for maximum brightness and use a 6V supply. That gives you 160mA. The circuit you have using the ULN2003A should work fine. Those can handle 500mA. Not sure what the inrush current is for those bulbs. If you want to know, just measure the cold temperature resistance across the bulb. When hot it is 6.3V/0.04A or 157 ohms. What is the cold reading with a DMM? This is important because it determines the inrush current for the bulb. If it is less than 6.3V/125mA that is 50 ohms, you will need to either consider a different driver part or add some sort of current limitation circuit. Keep in mind these will only have 1/4 the brightness over the original 28V ones, being they are only using 1/4 the power.

Thank you for your help! I appreciate it! Yes I beleive they are wired up in parallel as thats the original circuitry on the indicator itself, woule it be safe to run them through a 18V? as there are 4 in parallel? or is that not how it works?

 

Thank you for your help! I appreciate it! Yes I beleive they are wired up in parallel as thats the original circuitry on the indicator itself, woule it be safe to run them through a 18V? as there are 4 in parallel? or is that not how it works?

If you use 18V you cannot wire them in parallel. Each bulb is rated for 6.3V If you use 18V you could use that for the original bulbs that where capable of 28V max. In that case you could but the brightness would be decreased. If you use 28V and the original bulbs you will have maximum brightness. If you use the original bulbs at 18V not as bright, but inrush current will be less. At 28V 0.04A resistance is 700 ohms. Power is 1.12W. At 18V the power would be 0.46W so a little less than 1/2 normal brightness at 18V compared to 28V. When you wire the 6.3V ones in series, each bulb sees 18V/4 or 4.5V. Max brightness is a power of 0.25W per bulb. With 4 in series with 18V that gives you 0.13W so half the power and half the brightness.

 

In all cases you do have to consider the bulb's inrush current. That will determine the driver part needed. Measure the resistance of the bulb with a DMM, what is it? That will determine maximum inrush current.

 

In all cases you do have to consider the bulb's inrush current. That will determine the driver part needed. Measure the resistance of the bulb with a DMM, what is it? That will determine maximum inrush current.

Thank you! once I get one, any good recommendations? and work out how to do it I'll do it I'll reprt back! I might need your help in measuring the resitance.

I'm also considering getting 18V bulbs for max brightness

 

I haven't read through the entire thread, but ... you used to be able to buy direct drop-in LED replacements for midget flange and other indicator panel bulb types. Built-in current limiting resistor for specific operating voltages, but not cheap.

ak

 

I'm also considering getting 18V bulbs for max brightness

They might get too hot. I bought some Alco indicators and they changed the design so that a O-ring tightly fitted over the lamp. All 100 of them started to crumble and break. Idec to the rescue. 24 V AC or DC. Just had to buy the right color.

 

Thank you! once I get one, any good recommendations? and work out how to do it I'll do it I'll reprt back! I might need your help in measuring the resitance.

I'm also considering getting 18V bulbs for max brightness

I would recommend the 28V original bulbs with a 28V power supply (one I showed earlier) at around 18 bucks. But that is just my personal preference. Then you will have the original aircraft look. To measure the resistance you need a DMM? Not sure if you have one?

 

I would recommend the 28V original bulbs with a 28V power supply (one I showed earlier) at around 18 bucks. But that is just my personal preference. Then you will have the original aircraft look. To measure the resistance you need a DMM? Not sure if you have one?

No I dont have a DMM but I think that will be the next purchase and a soldering iron