Power supply project ideas.  - Page 1
Forum section: electronics / projects

author: Section8
author_rank: Contributor
timestamp: September 16, 2022, 12:04:49 am
content: Hi all,We've got a wee project at work which is a testing tool that imitates a car/truck. Its basically a pi in a box with a screen and the ability to talk to ODBII devices and impersonate car power.i've been asked to suggest some ideas to move our power supply from prebuilt modules to a switchmode power supply.We got our first prototype/proof of concept going with a couple of cheap power modules, but we want to go to something with a more mass producible design. Eventually we might want to make a couple of hundred of these things (one for every tester, dev, and possibly some for sales calls).RequirementsFixed 5v supply at up to 3ASwitchable vehicle power at 10.7v (turnover), 12.4v (ignition on) and 14.4v(engine on). <500ma.I've never designed a switchmode circuit before, so i'm a bit stuck.Can anyone point me to suitable switchmode circuits for this?What's the best way to adjust the output voltage of the vehicle power.Thanks,S8.

author: Jester
author_rank: Frequent Contributor
timestamp: September 16, 2022, 12:20:59 am
content: I have used TI Workbench in the past for this. It worked quite well

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 16, 2022, 12:54:30 am
content: If it's a one off, just buy a programmable bench PSU.

author: ledtester
author_rank: Super Contributor
timestamp: September 16, 2022, 01:00:24 am
content: Quote from: Section8 on September 16, 2022, 12:04:49 amHow much current do you need to produce to simulate the vehicle power?One possibility is something like a Riden DPH5005:https://www.aliexpress.com/item/3256803891892215.htmlYou can get it with a USB and/or Bluetooth interface which would allow the Raspberry Pi to control the output voltage.The DPH5005 converts an input voltage to the desired output voltage which can be either higher or lower. For instance, it could convert the 5V supply you are using for the Rpi to the vehicle voltage.QuoteDo you only have to output these three voltages or do you want to be able to simulate any voltage in between?

author: Section8
author_rank: Contributor
timestamp: September 16, 2022, 01:10:27 am
content: Its a one off at the moment, but eventually we want to produce a couple of hundred of these.

author: Section8
author_rank: Contributor
timestamp: September 16, 2022, 01:14:12 am
content: The vehicle power is mostly for the obd2 device, which might have gps in it as well.Lets say the cap on the vehicle power is 0.5A.We have used one of those units for the initial prototype, but if we can make it useful enough we'll want a couple of hundred of these things, so want to get away from just plugging modules together.

author: Section8
author_rank: Contributor
timestamp: September 16, 2022, 01:21:53 am
content: Thanks for the suggestions so far guys. I've added to my OP to clarify some of the goals.

author: LoveLaika
author_rank: Frequent Contributor
timestamp: September 16, 2022, 03:02:25 am
content: How do you plan to power your power supply?

author: rooppoorali
author_rank: Regular Contributor
timestamp: September 16, 2022, 08:16:49 am
content: I think you can consider this design.https://www.pcbway.com/project/shareproject/5v_3_3V_Power_Supply___LiPo_Charger.htmlThis one is a 5v/3.3V Power Supply for Raspberry Pi and IoT Projects. LiPo Battery charger and management system. It can output Maximum 3.8A.