[ginettaman]

Hi,

Has anyone done a parts list for the Steps v1.2 from a UK supplier?

The parts I'm finding hard to locate are Choke & Transformer.

Any further help from builders would be greatly received, first time into 240volt builds

 

[RJ2015]

Just building the STEPS1.2 and PPA2 myself at this moment, this is what I've ordered. The transformer I got is from RS-Components, part# 2239345. It's the same as mentioned on the partlist. The choke is from Farnell , part# 3227480, 0.4A 26mH, it's the best match I could find.

I'm at step 3

 

[guzzler]

Rapid Electronics stock a choke that will fit the board as well, cheaper than Farnell too.

http://www.rapidelectronics.co.uk/rk...3879&XPAGENO=1

 

[divie23]

Is this a suitable part from RS?
Part No: 173-6019

I'd rather get all the parts from one place.

Also I'm unsure about whether to get +/-12V or a +/-15V transformer.

I'm going to use it with a PPAv2 which should only take about 22V right?

Many thanks

 

[steinchen]

Quote:

Originally Posted by divie23 Is this a suitable part from RS? Part No: 173-6019

No, I'm afraid. The RN122 choke has a footprint of 15x25mm, for the v1.2 steps you need a choke with a 10x13mm footprint

Quote:

Originally Posted by divie23 Also I'm unsure about whether to get +/-12V or a +/-15V transformer.

as a rule of thumb: +-12V for a 24V psu and +-15V for a 30V psu, depending on rated wattage of the transformer and the current you are going to draw from the psu. Consult Tangent's Supply Parameter Estimator for details

Quote:

Originally Posted by divie23 I'm going to use it with a PPAv2 which should only take about 22V right?

Depends on the opamp you are going to use: 24V ... 30V is the usually picked range, more is possible (opa604) but not recommended

 

[divie23]

Thank you for your help stienchen.

I'll be using the OPA627/637 combo. I'm thinking that the +/- 12V is probably the safer option since I've already ordered the ELNa 470uF 25V caps for the PPA v2.

That should give me up to 24V which I'm hoping is plenty for the 627/637s.