Running a 12V VHF Radio off a 24V system?

[coopec43]

I am wondering how to run a 12V radio on a 24V system. Is this a possibility or am I completely confused?






XL4016 5-36V to 1.3-32V DC-DC Digital Voltage Regulator Buck Step Down Power Supply Module Over Temperature Protection

9A step-down module XL4016 (with/without constant current)

Module parameters:
Module properties: non-isolated step-down constant current, constant voltage module (CC CV) charging module
Scope of application: high-power LED constant current drive, lithium battery charging (including ferroelectric), 4V, 6V, 12V, 14V, 24V battery charging, Ni-Cd Ni-MH battery (battery pack) charging, solar panels, wind turbines
Input voltage: 7-32V (without constant current 5-32V) now the input voltage is 40V
Output voltage: (1) Continuously adjustable (0.8-28V) output voltage (1.2-35V)
(2) Fixed output (optional between 0.8-28V)
Output current: 12A (output current 8-9A) (if the temperature of the power tube exceeds 65 degrees, please add a fan for heat dissipation, 24V to 12V within 6A, generally no fan can be added in an open environment)
Constant current range: 0.2-12A (adjustable) (without constant current without this function) (output current 8-9A)
Turning light current: constant current value* (0.1), turning light current is linked with constant current value, for example, if the constant current value is 3A, the turning light current is set to 0.1 times the constant current (0.1*3A=0.3A). When the current value is adjusted to 2A, the turn lamp current is 0.1 times the constant current (0.1*2A=0.2A).
The second version is fixed 0.1 times (the actual turn light current is an approximate value, not very), which is used to indicate whether it is fully charged or not.
Dropout: 1V
Output power: The power is about 300W, please add a fan if the temperature of the power tube exceeds 65 degrees.
Conversion efficiency: about 95% (the higher the output voltage, the higher the efficiency)
Working frequency: 300KHZ (frequency 180KHZ)
Output ripple: 20M bandwidth (for reference only)
Input 24V output 12V 5A about 50mV ripple (no noise)
Working temperature: Industrial grade (-40℃ to +85℃) (Please pay attention to the temperature of the power tube in actual use, if the temperature is too high, please strengthen the heat dissipation)

https://www.aliexpress.com/item/1005003730699933.html?ug_edm_item_id=1005003730699 933&pdp_npi=2%2540dis!AUD!AU+%25244.15!AU+%25243.0 3!!!!!%25402102f5ff16642604016661001d3e66!12000028 321767174!edm&edm_click_module=alg_product_l1r2_78 80990280&creative_img_ind=1&tracelog=rowan&rowan_i d1=aeug_edm_41194_1_en_US_2022-10-18&rowan_msg_id=coopCOWS_41194_%25245069a21b40e143 67b175b3346a

[goboatingnow]

I have used the last mentioned unit to power a vhf radio. Just be aware the radio can draw considerable currents. I rigged a little computer fan to blow on the heatsink.

[tkeithlu]

QUOTE: "Input 24V output 12V 5A"

As goboatingnow mentions, the problem, if you have one, will be the 5 amp limit in your power supply. Pressing the PTT button could suck that down as if you had used inadequate wiring between the battery and the radio. Here's a $13/10 amp converter that you might consider:

https://www.amazon.com/EPBOWPT-Conve...347436439&th=1

I just looked up the current demand for a Hamilton Standard 25w VHF. It was 5.5 amps, so you'll be near the limit in any case. I recommend that you consider a 10 amp supply. Good luck with it.

[deblen]

https://www.defender.com/product.jsp...947&id=7055202

[s/v Jedi]

Get a sealed unit like this 20A: https://www.amazon.com/gp/product/B09GXXQZ6P

Edit: I tested these, they are the bees knees for these applications

[ForeverDes]

Originally Posted by s/v Jedi

Get a sealed unit like this 20A: https://www.amazon.com/gp/product/B09GXXQZ6P

Edit: I tested these, they are the bees knees for these applications

I agree wholeheartedly! I even have a 100 amp unit in my bow for the 12v windlass; it works flawlessly.

[goboatingnow]

Originally Posted by s/v Jedi

Get a sealed unit like this 20A: https://www.amazon.com/gp/product/B09GXXQZ6P

Edit: I tested these, they are the bees knees for these applications

Widely available on aliexpress , I used two in my last mobo , quite good

I have two of those open frame 5A in the current boat. Interesting both survived the lightening strike !!

[s/v Jedi]

Originally Posted by goboatingnow

Widely available on aliexpress , I used two in my last mobo , quite good

I have two of those open frame 5A in the current boat. Interesting both survived the lightening strike !!

I threw 30V in, then shorted the output and it survived

[CaptainRivet]

Originally Posted by ForeverDes

I agree wholeheartedly! I even have a 100 amp unit in my bow for the 12v windlass; it works flawlessly.

Who offers a 24V to 12V converter in real 100A?
The windlass has quite some current peak that’s normal 3-5x the continues current. That sounds like a very good Converter.

[CaptainRivet]

Originally Posted by tkeithlu

QUOTE: "Input 24V output 12V 5A"

As goboatingnow mentions, the problem, if you have one, will be the 5 amp limit in your power supply. Pressing the PTT button could suck that down as if you had used inadequate wiring between the battery and the radio. Here's a $13/10 amp converter that you might consider:

https://www.amazon.com/EPBOWPT-Conve...347436439&th=1

I just looked up the current demand for a Hamilton Standard 25w VHF. It was 5.5 amps, so you'll be near the limit in any case. I recommend that you consider a 10 amp supply. Good luck with it.

You can and I would bump up the voltage to 14,4 or even 14,7V. That way the VHF uses less ampere and it’s internal amps deliver more power. All 12V equipment is rated for minimum 15V.
That’s the sexy advantage when running 12V equipment in a 24V system, the buck converter can cover up the voltage drop and you can run the equipment on optimum voltage, especially if it’s a regulated buck converter. Eg pumps have a much longer life if they run at higher voltage and the voltage drop is low.
Have 12V system and got a Victron 12/12 30A regulated buck Converter very cheap, that sits now in the main power supply cable for the water pump and the Compressor fridge, bumping up the approx 12,8-13V to constant 14,7V and both running much better and cooler.

[smac999]

Since the vhf is one of the most important things in the boat. You certainly don’t use that cheap crap.

Look at the victron Orion 24-12. More then 10a.

If you plan on adding more 12v stuff later. Maybe grab something bigger like the 30a.

[coopec43]

Originally Posted by smac999

Since the vhf is one of the most important things in the boat. You certainly don’t use that cheap crap.

Look at the victron Orion 24-12. More then 10a.

If you plan on adding more 12v stuff later. Maybe grab something bigger like the 30a.

"Great minds think alike!" (Anon) Yes I agree with you.

Maybe I will want to add other "stuff" later. I checked out some links and I find I can get a 30A DC/DC Converter Regulator for just a few dollars more than a 20A unit.

https://www.ebay.com.au/itm/384655904415

[mako]

How about install two VHF radios in series?

[coopec43]

Originally Posted by mako

How about install two VHF radios in series?

Not sure what you mean but it sounds like a great idea.
Do you mean something like this? (Could you please explain?)

MFJ Duplexer--Two radios, one antenna, or vice versa

https://www.youtube.com/watch?v=i9ttJn7Qy_s

https://electronics.stackexchange.co...in-an-am-radio

[Wotname]

Or you could simply use a 24V VHF radio.
IIRC, Icom, Sailor, Furuno, all make 24V VHF radios and maybe JRC and SEA do as well.