Sorry but the text: "The circuit 1 requires ''2 power on'' to switch on my product while circuit 2 only require ''1 power on'' to switch on the same product." and: "-> = Connected to Circuit 1: 24Vdc -> DC/DC converter -> 12Vdc Circuit 2: 24Vdc -> DC/AC Inverter -> 230Vac -> AC/DC -> 12Vdc" is pretty much meaningless without information about what it refers to. You need to post links to where these parts are in the EasyEDA libraries or manufacturer's or suppliers pages and links to datasheets where possible to provide enough information from which to make a meaningful assessement. Please read: [https://easyeda.com/forum/topic/How-to-ask-for-help-and-get-an-answer-71b17a40d15442349eaecbfae083e46a](https://easyeda.com/forum/topic/How-to-ask-for-help-and-get-an-answer-71b17a40d15442349eaecbfae083e46a) then post back with the links to relevant information and to an example public project to illustrate your question.

Hi andyfierman, Firstly, thank you for taking your time to see through this post, what i mean by power on is the switching on from the product which i am unable to have access to. As a result, i am only able to give a vague explanation of what has happened during the experimentation. The main question would be the circuit difference in general. As from my understanding, both circuit converts a 24Vdc to 12Vdc. Thanks!

@ricxon, Without a clearer understanding of what the two types of power converter are it is very hard to say other than pure speculation. You need to at least describe: what "the product" is; exactly how it is wired up and to what; exactly what steps you are taking when you talk about "the switching on from the product" otherwise sorry but this is just wasting everyone's time.

@andyfierman Thank you for the time, but i am unable to provide more details. What i wanted is indeed the speculation of what are the possible differences in circuit hence saying ''any input for potential causes''. These are all the information that I am able to share. Therefore, the main question as mention in the post "the differences in the circuit (example: Pros and Cons) aside for the cost and package sizing'' is a generic question on the 2 circuits where both are stepping down voltage from 24Vdc to 12Vdc and not an in-depth analysis of any circuit. -> = Connected to Circuit 1: 24Vdc -> DC/DC converter -> 12Vdc Circuit 2: 24Vdc -> DC/AC Inverter -> 230Vac -> AC/DC -> 12Vdc I am sorry for wasting your time.

@ricxon, Your question is like me saying that there are two cars about which all I can tell you is that one is an automatic and the other is manual geared. Please discuss the pros and cons. So, in the following discussion it is assumed that: * All circuits are competently designed;  * All circuits are designed for maximum efficiency in terms of power conversion (i.e. linear regulation is not used). * Neither circuit includes any non-electronic energy storage devices or systems. **Circuit 1: ** **Pro:** 1. Fewer power conversion stages (1: 24VDC to 12VDC);  2. More electrically efficient;  3. Easier to cool;  4. Simpler to design for EMC;  5. Simpler to design for LVD;  6. Fewer components;  7. Fewer failure modes;  8. Higher reliability; **Con:** 1. Only available in Beige with Brown upholstery. <br> <br> **Circuit 2: ** **Pro:** 1. Possibility to be assembled from off the shelf modules;  2. Possibility for 12VDC to be supplied from either 24VDC or 230VAC. 3. Possibility to use the 230VAC to generate high internal voltage used for capacitive energy stotage (Energy in a Capacitor C charged to a voltage V = 0.5*C*V^2) **Con:** 1. Several power conversion stages (at least 3: 24VDC to 230VAC, 230VAC to some intermediate DC, intermediate DC to 12VDC);  2. Lower overall electrical efficiency;  3. Increased cooling requirements;  4. Harder to design for EMC (several internal switching frequencies);  5. More complex to design for LVD (internal voltages > 48V); 6. Higher component count;  7. Higher number of failure modes;  8. Lower reliability; 9. Increased risk of fire and explosion due to manufacturing procurement sourcing cheap off the shelf modules that do not meet the original safety and reliability requirements.

@andyfierman Thank you sir for your input! really appreciate it.